Sample records for anechoic chamber facility

  1. An anechoic chamber facility for investigating aerodynamic noise

    NASA Technical Reports Server (NTRS)

    Massier, P. F.; Parthasarathy, S. P.

    1972-01-01

    The aerodynamic noise facility was designed to be used primarily for investigating the noise-generating mechanisms of high-temperature supersonic and subsonic jets. The facility consists of an anechoic chamber, an exhaust jet silencer, instrumentation equipment, and an air heater with associated fuel and cooling systems. Compressed air, when needed for jet noise studies, is provided by the wind tunnel compressor facility on a continuous basis. The chamber is 8.1 m long, 5.0 m wide, and 3.0 m high. Provisions have been made for allowing outside air to be drawn into the anechoic chamber in order to replenish the air that is entrained by the jet as it flows through the chamber. Also, openings are provided in the walls and in the ceiling for the purpose of acquiring optical measurements. Calibration of the chamber for noise reflections from the wall was accomplished in octave bands between 31.2 Hz and 32 kHz.

  2. Perspectives on anechoic chamber qualification

    Microsoft Academic Search

    Kenneth A. Cunefare; Van B. Biesel

    2002-01-01

    The qualification of a new anechoic chamber requires demonstration that the chamber produces a free-field environment within some tolerance bounds and over some acceptable volume. At the most basic level, qualification requires measurement of sound levels at increasing distances from a test source, and then comparing the levels to a theoretical free-field decay. While simple in concept, the actual performance

  3. Design and characterization of an anechoic aeroacoustic facility

    Microsoft Academic Search

    Jose Mathew; Chris Bahr; Bruce Carroll; Mark Sheplak; Lou Cattafesta

    2005-01-01

    The design and characterization of an anechoic wind tunnel facility at the University of Florida are presented. A previously existing and ISO 3745 validated 100-Hz anechoic chamber is upgraded to incorporate an open-jet anechoic wind tunnel facility suitable for airframe noise studies, including swept-wing trailing edge studies. For suitable modeling of landing conditions, a chord-based Reynolds number of 3 to

  4. ANALYSIS OF ANECHOIC CHAMBER TESTING OF THE HURRICANE IMAGING RADIOMETER

    E-print Network

    Ruf, Christopher

    conducted in an anechoic chamber using a broadband noise diode as a transmitting source. In additionANALYSIS OF ANECHOIC CHAMBER TESTING OF THE HURRICANE IMAGING RADIOMETER David Fenigstein1 , Chris the measurement in an anechoic chamber of antenna-pair interference patterns. This paper describes the procedures

  5. A Portable Anechoic Chamber for PAD Use

    Microsoft Academic Search

    F. W. Hutchinson; A. J. Lazarewicz

    1963-01-01

    The design and construction of a small light-weight anechoic chamber for testing the first orbiting rendezvous radar on a launching pad are described. Performance and weight considerations were evaluated and a practical compromise was reached. A chamber capable of measuring L-band radar angular accuracy and weighing only slightly more than 100 pounds was the result. Radar RF go, no-go checks

  6. The ARL\\/FED anechoic chamber

    Microsoft Academic Search

    R. C. Marboe; J. M. Fitzgerald

    1981-01-01

    This report documents the design and acoustic characteristics of the Applied Research Laboratory Department anechoic chamber. It is located on the above-console deck of the Garfield Thomas Water Tunnel situated so as to allow its use in conjunction with the Axial Flow Research Fan (AFRF). The internal free dimensions of the chamber are 2.74 x 3.05 x 1.98 meters (9

  7. An anechoic chamber for SHF and EHF bands

    NASA Astrophysics Data System (ADS)

    Fujino, Yoshiyuki; Fujita, Masaharu

    1995-06-01

    A small scale radio anechoic chamber was constructed for antenna measurement and/or EMC measurement in the SHF and EHF bands. This paper summarizes special features of the anechoic chamber, and gives detailed explanations of the chamber, measurement system, and measurement software.

  8. Compact anechoic chamber for immunity test and EMI noise measurement

    Microsoft Academic Search

    K. Ishino; Y. Hashimoto; M. Okamura; Y. Shimizu

    1991-01-01

    The distribution of the electromagnetic field in the compact anechoic chamber consisting of four walls, ceiling, and floor with ferrite absorbing materials was investigated. The compact anechoic chamber used for both immunity test and electromagnetic interference (EMI) noise measurement was developed by improved ferrite absorber. The compact chamber was extremely uniform, and the maximum deviation is less than 6 dB

  9. Anechoic chamber evaluation using the matrix pencil method

    Microsoft Academic Search

    B. Fourestie; Z. Altman; M. Kanda

    1999-01-01

    A new method for evaluation of an anechoic chamber using the matrix pencil method is presented. A signal measured between two antennas placed in an anechoic chamber is sliced into small frequency intervals and is processed using the matrix pencil method. In each interval, the measured signal is decomposed into its propagating-wave components, which correspond to a direct propagation between

  10. Reflectivity level of anechoic chambers at 183 GHz

    Microsoft Academic Search

    A. Lehto; J. Tuovinen; A. Raisanen

    1990-01-01

    The reflectivity levels of the anechoic chamber of the Helsinki University of Technology and the two chambers of the Technical Research Centre of Finland were measured at 183 GHz. Typical values of the reflectivity level of the tested chambers at 183 GHz are below -50 dB at moderate azimuth angles (<50°) and -45 dB at large angles (?90°) measured with

  11. Characteristics of an anechoic chamber for fan noise testing

    NASA Technical Reports Server (NTRS)

    Wuzyniak, J. A.; Shaw, L. M.; Essary, J. D.

    1977-01-01

    Acoustical and mechanical design features of NASA Lewis Research Center's engine fan noise facility are described. Acoustic evaluation of the chamber, which is lined with an array of stepped wedges, is described. Results from the evaluation in terms of cut-off frequency and non-anechoic areas near the walls are detailed. Fan models are electrically driven to 20,600 RPM in either the inlet mode or exhaust mode to facilitate study of both fore and aft fan noise. Inlet noise characteristics of the first fan tested are discussed and compared to full-scale levels. Turbulence properties of the inlet flow and acoustic results are compared with and without a turbulence reducing screen over the fan inlet.

  12. Fiber optic interferometric sensors for aeroacoustic measurements: anechoic chamber tests

    Microsoft Academic Search

    Young C. Cho; Maria G. Bualat

    1994-01-01

    We report here progress on a NASA program to develop fiber optic interferometric sensors for aeroacoustic measurements. As reported earlier, NASA's first fiber-optic microphone was developed and fabricated. Preliminary anechoic chamber tests demonstrated successfully its feasibility as an aeroacoustic sensor. Improved performance of a newly designed sensor head is presented here in terms of frequency response function and noise floor.

  13. The Design and Evaluation of an Economically Constructed Anechoic Chamber

    Microsoft Academic Search

    David Sun; Craig Jin; André van Schaik; Densil Cabrera

    2009-01-01

    This paper reports on a study of the design of an economic anechoic chamber so that a controlled environment would be readily available for acoustic experiments such as 3-D audio playback through a spherical loudspeaker array. It describes measurements performed to evaluate the room's acoustical performance against ISO 3745 and some ITU-R BS.1116-1 recommendations. Two custom omnidirectional sound sources were

  14. Analysis of Anechoic Chamber Testing of the Hurricane Imaging Radiometer

    NASA Technical Reports Server (NTRS)

    Fenigstein, David; Ruf, Chris; James, Mark; Simmons, David; Miller, Timothy; Buckley, Courtney

    2010-01-01

    The Hurricane Imaging Radiometer System (HIRAD) is a new airborne passive microwave remote sensor developed to observe hurricanes. HIRAD incorporates synthetic thinned array radiometry technology, which use Fourier synthesis to reconstruct images from an array of correlated antenna elements. The HIRAD system response to a point emitter has been measured in an anechoic chamber. With this data, a Fourier inversion image reconstruction algorithm has been developed. Performance analysis of the apparatus is presented, along with an overview of the image reconstruction algorithm

  15. REFLECTIVITY CHARACTERIZATION AND IDENTIFICATION OF PRIMARY REFLECTION PATH IN ANECHOIC CHAMBER ANALYSIS

    E-print Network

    Arakaki, Dean Y.

    REFLECTIVITY CHARACTERIZATION AND IDENTIFICATION OF PRIMARY REFLECTION PATH IN ANECHOIC CHAMBER ABSTRACT This paper presents an analysis of the reflectivity performance of the anechoic chamber and worst-case VSWR test measurements is within 1dB for a majority of reflection angles. In addition

  16. Ambient measurements in a semi-anechoic chamber

    Microsoft Academic Search

    J. Neal; K. P. Slattery; S. V. Smith

    1994-01-01

    In order to develop the automotive system control modules required in modern vehicles, an engineering department must have access to test and measurement facilities. These facilities must deliver, in a timely manner, data that truly reflects the spectral characteristics of the modules submitted for test. For that to happen, the engineers in charge of the test chambers must have a

  17. Electronic warfare testing at the Benefield anechoic facility

    Microsoft Academic Search

    Emad F. Ali; Pat Dubria; Bob Barker

    1997-01-01

    This paper discusses the test capabilities of the Benefield Anechoic Facility (BAF) and its mission to support avionics and electronic warfare (EW) test and evaluation (T&E) of current and future generation manned and unmanned aerospace vehicles. Testing at the BAF can provide the dense, complex, and realistic signal environment necessary to evaluate integrated systems\\/subsystems to meet both Development Test and

  18. The New Anechoic Shielded Chambers Designed for Space and Commercial Applications at LIT

    NASA Technical Reports Server (NTRS)

    da Silva, Benjamim; Galvao, M. C.; Pereira, Clovis Solano

    2008-01-01

    The main objective of this paper is to present the capabilities of the new anechoic shielded rooms designed for space and commercial applications as part of the Integration and Testing Laboratory (LIT, Laboratorio de Integracao e Testes) in Brazil. A new anechoic shielded room named CBA2 has been in full operation since March 2007 and a remodeled chamber CBA1 is planned to be ready by the end of 2008, replacing an old facility which was in operation for the last 18 years. The Brazilian Space Program started with very small and simple satellites and the old CBA1 chamber was conceived in 1987 to accomplish the EMI/EMC tests not requiring significant volumes. Since the very beginning this facility was also used by the private sector for other applications mainly due to the absorption of digital electronics in all kind of products. The intense use of this facility during the last years, operating three shifts a day, caused a normal degradation and imposed several limitations. Therefore, a new totally remodeled chamber was designed considering the state of the art in terms of absorbers and associated instrumentation. On the other hand the facility CBA2 was conceived, designed and implemented to test large satellites taking into account the advance of the technology in terms of RF frequencies, power level, testing methodologies and several other factors. A very interesting and unique aspect of this project was the partnership between the private sector and governmental institution. As a result, the total investment was shared between several companies and consequently a time-sharing use of the facility as well.

  19. Inlet noise on 0.5-meter-diameter NASA QF1 fan as measured in an unmodified compressor aerodynamic test facility and in an anechoic chamber

    Microsoft Academic Search

    T. F. Gelder; R. F. Soltis

    1975-01-01

    Narrowband analysis revealed grossly similar sound pressure level spectra in each facility. Blade passing frequency (BPF) noise and multiple pure tone (MPT) noise were superimposed on a broadband (BB) base noise. From one-third octave bandwidth sound power analyses the BPF noise (harmonics combined), and the MPT noise (harmonics combined, excepting BPF's) agreed between facilities within 1.5 db or less over

  20. The anechoic chamber at the laboratorio de Acústica y Luminotecnia CIC

    Microsoft Academic Search

    A. G. Velis; H. G. Giuliano; A. M. Méndez

    1995-01-01

    This paper describes the new anechoic chamber at the Laboratorio de Acústica y Luminotecnia of the Comisión de Investigaciones Cientificas de la Provincia de Buenos Aires (República Argentina) and the evaluation made to establish its performance. The chamber has a free working space of about 7 × 6 × 6 m. The evaluation made shows that the maximum deviation of

  1. Comparison of measurements of the characteristics of directional microphone hearing aids in an IAC test room and an anechoic chamber.

    PubMed

    Brey, R H; Caustin, E I; McPherson, J H

    1977-01-01

    The purpose of this study was to assess the possibility of measuring directional microphone hearing aids (DMHAs) using standard hearing aid test instruments in a sound field environment. The use of DMHAs is increasing and research has shown that under certain difficult listening situations, superior results are obtained by hearing impaired individuals with directional versus omnidirectional microphone arrangements. However, valid electroacoustic evaluation of the DMHAs cannot be accomplished using the conventional hearing aid test box. The ideal environment for such evaluations is an anechoic chamber, a facility not found in most audiological clinics. Results show that if the proper precautions are observed, the electroacoustic characteristics of DMHAs can be measured in a sound field environment using conventional hearing aid test instrumentation. Validation of this procedure was carried out by comparing sound field results with those obtained in an anechoic chamber. PMID:853009

  2. Anechoic Chamber test of the Electromagnetic Measurement System ground test unit

    SciTech Connect

    Stevenson, L.E.; Scott, L.D.; Oakes, E.T.

    1987-04-10

    The Electromagnetic Measurement System (EMMS) will acquire data on electromagnetic (EM) environments at key weapon locations on various aircraft certified for nuclear weapons. The high-frequency ground unit of the EMMS consists of an instrumented B61 bomb case that will measure (with current probes) the localized current density resulting from an applied EM field. For this portion of the EMMS, the first system test was performed in the Anechoic Chamber Facility at Sandia National Laboratories, Albuquerque, New Mexico. The EMMS pod was subjected to EM radiation at microwave frequencies of 1, 3, and 10 GHz. At each frequency, the EMMS pod was rotated at many positions relative to the microwave source so that the individual current probes were exposed to a direct line-of-sight illumination. The variations between the measured and calculated electric fields for the current probes with direct illumination by the EM source are within a few db. The results obtained from the anechoic test were better than expected and verify that the high frequency ground portion of the EMMS will accurately measure the EM environments for which it was designed.

  3. Anechoic Chamber test of the Electromagnetic Measurement System ground test unit

    NASA Astrophysics Data System (ADS)

    Stevenson, L. E.; Scott, L. D.; Oakes, E. T.

    1987-04-01

    The Electromagnetic Measurement System (EMMS) will acquire data on electromagnetic (EM) environments at key weapon locations on various aircraft certified for nuclear weapons. The high-frequency ground unit of the EMMS consists of an instrumented B61 bomb case that will measure (with current probes) the localized current density resulting from an applied EM field. For this portion of the EMMS, the first system test was performed in the Anechoic Chamber Facility at Sandia National Laboratories, Albuquerque, New Mexico. The EMMS pod was subjected to EM radiation at microwave frequencies of 1, 3, and 10 GHz. At each frequency, the EMMS pod was rotated at many positions relative to the microwave source so that the individual current probes were exposed to a direct line-of-sight illumination. The variations between the measured and calculated electric fields for the current probes with direct illumination by the EM source are within a few db. The results obtained from the anechoic test were better than expected and verify that the high frequency ground portion of the EMMS will accurately measure the EM environments for which it was designed.

  4. Satellite Radiometer Pre-launch Sensitivity Estimation using Anechoic Chamber and Channel Intercomparison

    Microsoft Academic Search

    Andreas Colliander; Manuel Martín-Neira; Josep Closa; Francisco-Javier Benito

    2009-01-01

    The sensitivity of a radiometer to the brightness temperature variations of the target is one of the critical parameters of any radiometric measurement. The sensitivity is limited by the noise in the measurement and the stability of the instrument. In this study measurements in an anechoic chamber are used to evaluate the sensitivity limit of radiometers, which are the noise

  5. AIAA 2004-0010 Designing an Anechoic Chamber for

    E-print Network

    Tinney, Charles E.

    12in. thick single poured concrete. All interior surfaces of the chamber are acoustically treated fiberglass held in place by perforated (46% solidity) metal sheeting. This was necessary to reduce any noise

  6. Design and analysis of a hemi-anechoic chamber at Michigan Technological University

    Microsoft Academic Search

    Jason Dreyer; Ashish Jangale; Mohan D. Rao

    2005-01-01

    A four-wheel chassis roll dynamometer test facility was installed on the campus of Michigan Technological University (MTU). The chassis dynamometer was enclosed in a soundproof hem-anechoic room in order to conduct noise radiation measurements on test vehicles. All surfaces of the room, except the floor and control room window, were acoustically treated with donated tetrahedral acoustic cones and panels. The

  7. Radar cross section measurements of complex targets (missile parts) in C-band in anechoic chamber

    Microsoft Academic Search

    Marcelo A. S. Miacci; Inácio M. Martin; Mirabel C. Rezende

    2007-01-01

    Assembly of an experimental setting necessary to measure the radar cross section (RCS) of simple and complex targets was accomplished in an anechoic chamber using an active noise suppression system, by using the C-band of frequencies (5.0 to 7.0 GHz). As results of this Brazilian pioneer work in the area of electromagnetic characterization, the diagrams of the radar cross section

  8. Wideband numerical modelling and performance optimisation of arbitrarily-shaped anechoic chambers via an unconditionally stable time-domain technique

    Microsoft Academic Search

    Nikolaos V. Kantartzis; Theodoros D. Tsiboukis

    2005-01-01

    A 3-D curvilinear alternating-direction implicit finite-difference time-domain (ADI-FDTD) algorithm for the broadband analysis and optimised design of anechoic and semi-anechoic chambers with arbitrary shape is presented in this paper. The unconditionally stable and frequency-dependent method develops a new family of spatial\\/temporal forms which reduce the critical dispersion errors of existing approaches and allow the precise performance evaluation of essential components

  9. A microwave applicator for uniform irradiation by circularly polarized waves in an anechoic chamber

    SciTech Connect

    Chiang, W. Y.; Wu, M. H.; Wu, K. L.; Lin, M. H.; Teng, H. H.; Barnett, L. R.; Chu, K. R., E-mail: krchu@yahoo.com.tw [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Tsai, Y. F.; Ko, C. C.; Yang, E. C. [Department of Entomology, National Taiwan University, Taipei, Taiwan (China); Jiang, J. A. [Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei, Taiwan (China)

    2014-08-15

    Microwave applicators are widely employed for materials heating in scientific research and industrial applications, such as food processing, wood drying, ceramic sintering, chemical synthesis, waste treatment, and insect control. For the majority of microwave applicators, materials are heated in the standing waves of a resonant cavity, which can be highly efficient in energy consumption, but often lacks the field uniformity and controllability required for a scientific study. Here, we report a microwave applicator for rapid heating of small samples by highly uniform irradiation. It features an anechoic chamber, a 24-GHz microwave source, and a linear-to-circular polarization converter. With a rather low energy efficiency, such an applicator functions mainly as a research tool. This paper discusses the significance of its special features and describes the structure, in situ diagnostic tools, calculated and measured field patterns, and a preliminary heating test of the overall system.

  10. A microwave applicator for uniform irradiation by circularly polarized waves in an anechoic chamber

    NASA Astrophysics Data System (ADS)

    Chiang, W. Y.; Wu, M. H.; Wu, K. L.; Lin, M. H.; Teng, H. H.; Tsai, Y. F.; Ko, C. C.; Yang, E. C.; Jiang, J. A.; Barnett, L. R.; Chu, K. R.

    2014-08-01

    Microwave applicators are widely employed for materials heating in scientific research and industrial applications, such as food processing, wood drying, ceramic sintering, chemical synthesis, waste treatment, and insect control. For the majority of microwave applicators, materials are heated in the standing waves of a resonant cavity, which can be highly efficient in energy consumption, but often lacks the field uniformity and controllability required for a scientific study. Here, we report a microwave applicator for rapid heating of small samples by highly uniform irradiation. It features an anechoic chamber, a 24-GHz microwave source, and a linear-to-circular polarization converter. With a rather low energy efficiency, such an applicator functions mainly as a research tool. This paper discusses the significance of its special features and describes the structure, in situ diagnostic tools, calculated and measured field patterns, and a preliminary heating test of the overall system.

  11. Some acoustical properties of the anechoic chamber at the Centro de Instrumentos, Universidad Nacional Autónoma de México

    Microsoft Academic Search

    Ricardo R Boullosa; A Pérez López

    1999-01-01

    Some of the basic acoustical properties of an anechoic chamber recently brought to operation are described. The background noise levels and sound insulation of doors were measured. The free field conditions in different directions and frequencies were determined using nondirectional sources.

  12. Filtering environmental reflections in far-field antenna measurement in semi-anechoic chambers by an adaptive pattern strategy

    Microsoft Academic Search

    M. D. Migliore

    2004-01-01

    A method to perform antenna far-field measurements in semi-anechoic chamber is presented. The method requires the measurement of the amplitude and phase of the pattern of the antenna under test in different spatial positions. The data are elaborated to estimate the direction of arrival of the reflected signals and to synthesize a receiving pattern with s in these directions. Experimental

  13. A hybrid scheme of signal process techniques to improve the measurement accuracy of antenna radiation patterns inside an anechoic chamber

    Microsoft Academic Search

    2006-01-01

    Antenna measurement inside an anechoic chamber can significantly suffer from measurement inaccuracy due to the scattering from the shielding walls and internal structures, if the space is not sufficiently large and the absorbers have not significantly reduced the multipath signals, which raises multipath interference. This paper develops a hybrid scheme that integrates the concepts of signal processing techniques including time

  14. Calibration of the Ames Anechoic Facility. Phase 1: Short range plan

    NASA Technical Reports Server (NTRS)

    Hickey, D.; Soderman, P. T.; Karamcheti, K.; Koutsoyannis, S. P.; Hopkins, R.; Mclachlan, B.

    1980-01-01

    A calibration was made of the acoustic and aerodynamic characteristics of a small, open-jet wind tunnel in an anechoic room. The jet nozzle was 102 mm diameter and was operated subsonically. The anechoic-room dimensions were 7.6 m by 5.5 m by 3.4 m high (wedge tip to wedge tip). Noise contours in the chamber were determined by various jet speeds and exhaust collector positions. The optimum nozzle/collector separation from an acoustic standpoint was 2.1 m. Jet velocity profiles and turbulence levels were measured using pressure probes and hot wires. The jet was found to be symmetric, with no unusual characteristics. The turbulence measurements were hampered by oil mist contamination of the airflow.

  15. Antenna height scan for minimizing EUT emission measurement uncertainty in fully anechoic chambers above 1 GHz

    Microsoft Academic Search

    Tian Hong Loh; M. Alexander

    2006-01-01

    Our aim in this research work is to propose a methodology on receiving antenna height scan in the fully anechoic room (FAR) to minimize uncertainty in obtaining maximum emission of equipments under test (EUT) that have multilobe radiation patterns at higher frequencies. An EUT with complex slots is measured. The radiation emission for five antenna heights from 1 m to

  16. Investigation on High Performance of 10m Semi Anechoic Chamber by using Open-Top Hollow Pyramidal Hybrid EM Wave Absorber

    NASA Astrophysics Data System (ADS)

    Kurihara, Hiroshi; Saito, Toshifumi; Suzuki, Yoshikazu; Nishikata, Atsuhiro; Hashimoto, Osamu

    The emission radiated from electric and electronic equipments is evaluated through OATS. Recently, it is not fully prepared the environment for OATS because of a variety of communication radiation sources (e.g., digital television broadcast and cellular phone station). Therefore, the EM anechoic chambers are becoming more and more important as EMI test site. On the other hand, the EM anechoic chambers are needed high performance in order to cut down EMI countermeasure cost and calculate the antenna factor. The objective of this paper is mainly to present the EM wave absorber design in order to obtain within ±2dB against the theoretical site attenuation values in the 10m semi anechoic chamber at 30MHz to 300MHz. We get the necessary reflectivity of EM wave absorber by the basic site attenuation equation. We design the open-top hollow pyramidal new hybrid EM wave absorber consisted of 180cm long dielectric loss foam and ferrite tiles. Then, we design the 10m semi anechoic chamber by using the ray-tracing simulation and construct it in the size of L24m×W15.2m×H11.2m. More over, we measure the site attenuation of the constructed 10m semi anechoic chamber by using the broadband calculable dipole antennas. As the result, we confirm the validity of the designed open-top hollow pyramidal new hybrid EM wave absorber.

  17. Implementation of an Active Noise Cancellation System in RCS Measurements of Complex Targets in the C Band using an Anechoic Chamber

    Microsoft Academic Search

    Marcelo A. S. Miacci; Inácio Malmonge Martin; Mirabel C. Rezende

    This work presents the improvement design of a Radar Cross Section (RCS) measurement system of complex shapes targets (missiles), with the development of an active noise cancellation system. The RCS measurements were carried out in indoor ambient, in a quasi-monostatic condition, using an anechoic chamber, in the frequency range of 5.8 to 6.4 GHz (C-band). Experimental results of missile section

  18. Prediction of the scattering of a double periodic array of anechoic chamber pyramids by a surface integral equation approach

    Microsoft Academic Search

    N. Marly; D. De Zutter; L. Martens; H. Pues

    1993-01-01

    The scattering and absorption of a double periodic array of anechoic room pyramids backed by a perfect conductor is analyzed with a surface integral equation (SIE) approach. The use of a suitable periodic Green's function as the kernel of the SIE reduces the formulation of the problem of a single pyramid. The validity, flexibility, and accuracy of the SIE approach

  19. Indian LSSC (Large Space Simulation Chamber) facility

    NASA Technical Reports Server (NTRS)

    Brar, A. S.; Prasadarao, V. S.; Gambhir, R. D.; Chandramouli, M.

    1988-01-01

    The Indian Space Agency has undertaken a major project to acquire in-house capability for thermal and vacuum testing of large satellites. This Large Space Simulation Chamber (LSSC) facility will be located in Bangalore and is to be operational in 1989. The facility is capable of providing 4 meter diameter solar simulation with provision to expand to 4.5 meter diameter at a later date. With such provisions as controlled variations of shroud temperatures and availability of infrared equipment as alternative sources of thermal radiation, this facility will be amongst the finest anywhere. The major design concept and major aspects of the LSSC facility are presented here.

  20. X-43A Undergoing Controlled Radio Frequency Testing in the Benefield Anechoic Facility at Edwards Ai

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The X-43A Hypersonic Experimental (Hyper-X) Vehicle hangs suspended in the cavernous Benefield Aenechoic Facility at Edwards Air Force Base during radio frequency tests in January 2000. Hyper-X, the flight vehicle for which is designated as X-43A, is an experimental flight-research program seeking to demonstrate airframe-integrated, 'air-breathing' engine technologies that promise to increase payload capacity for future vehicles, including hypersonic aircraft (faster than Mach 5) and reusable space launchers. This multiyear program is currently underway at NASA Dryden Flight Research Center, Edwards, California. The Hyper-X schedule calls for its first flight later this year (2000). Hyper-X is a joint program, with Dryden sharing responsibility with NASA's Langley Research Center, Hampton, Virginia. Dryden's primary role is to fly three unpiloted X-43A research vehicles to validate engine technologies and hypersonic design tools as well as the hypersonic test facility at Langley. Langley manages the program and leads the technology development effort. The Hyper-X Program seeks to significantly expand the speed boundaries of air-breathing propulsion by being the first aircraft to demonstrate an airframe-integrated, scramjet-powered free flight. Scramjets (supersonic-combustion ramjets) are ramjet engines in which the airflow through the whole engine remains supersonic. Scramjet technology is challenging because only limited testing can be performed in ground facilities. Long duration, full-scale testing requires flight research. Scramjet engines are air-breathing, capturing their oxygen from the atmosphere. Current spacecraft, such as the Space Shuttle, are rocket powered, so they must carry both fuel and oxygen for propulsion. Scramjet technology-based vehicles need to carry only fuel. By eliminating the need to carry oxygen, future hypersonic vehicles will be able to carry heavier payloads. Another unique aspect of the X-43A vehicle is the airframe integration. The body of the vehicle itself forms critical elements of the engine. The forebody acts as part of the intake for airflow and the aft section serves as the nozzle. The X-43A vehicles were manufactured by Micro Craft, Inc., Tullahoma, Tennessee. Orbital Sciences Corporation, Chandler, Arizona, built the Pegasus rocket booster used to launch the X-43 vehicles. For the Dryden research flights, the Pegasus rocket booster and attached X-43 will be air launched by Dryden's B-52 'Mothership.' After release from the B-52, the booster will accelerate the X-43A vehicle to the established test conditions (Mach 7 to 10) at an altitude of approximately 100,000 feet where the X-43 will separate from the booster and fly under its own power and preprogrammed control.

  1. Reflections in anechoic rooms

    Microsoft Academic Search

    M. P. M. Luykx; M. L. S. Vercammen

    Anechoic rooms have to fulfil anechoic conditions to ensure that measurements are taken in a (almost) perfect free field. The practical use of the room however requires the presence of potentially reflecting elements that disturb the sound field. ISO 3745 prescribes a qualification method to assess the quality of anechoic rooms using a continuously moving microphone. Measurements have been made

  2. Calibration of fully anechoic rooms and correlation with OATS measurements

    Microsoft Academic Search

    R. A. McConnell; C. Vitek

    1996-01-01

    Fully anechoic rooms may gradually replace open area test sites as the preferred type of testing facility for the measurement of radiated emissions. The fully anechoic room offers several advantages over the open area test site. Immunity to high ambient signal levels, the capability of being located in metropolitan areas close to the customer base, more uniform field over a

  3. A Dedicated Radar Imaging Statistical Model of the Sinclair Matrix Initially Characterised in an Anechoic Chamber: Application To the Huynen Parameters Sensitivity Analysis - Summary

    Microsoft Academic Search

    L. Priou; B. Uguen; G. Chassay

    1997-01-01

    A noise Sinclair matrix statistical model of the Anechoïc Chamber measurement channel is first developed in the frequency domain, then in the time domain and finally in the holographic radar images domain. Building these models allows one to analyse the sensitivity of a common target classification tool, the Huynen parameters, for any target and then to construct a prediction model

  4. A dedicated radar imaging statistical model of the scattering matrix initially characterised in an anechoic chamber - Application to the Huynen parameters sensitivity analysis

    Microsoft Academic Search

    L Priou; B Uguen; G Chassay

    1996-01-01

    A noise scattering matrix statistical model of the Anechoïc Chamber measurement channel is first developed in the frequential domain, then in the time domain and in the holographic radar images domain. Building these models allows one to analyse the sensitivity of a common target classification tool, the Huynen parameters, for any target and then to construct a prediction model of

  5. Conversion of semi to fully anechoic rooms per CENELEC prEN50147-3

    Microsoft Academic Search

    M. A. K. Wiles; W. Mullner

    2001-01-01

    Many small to medium sized EMC anechoic chambers today are built as fully-anechoic rooms (FAR). The current draft prEN50147-3 standard by CENELEC TC210A\\/WG4 defines FAR validation and product measurement methods. The feasibility of converting a standard full-sized 3 m semi-anechoic room (SAR) to a compliant FAR is examined in this paper

  6. Acoustic measurements above an insufficiently absorbing flat surface or in imperfectly anechoic rooms

    Microsoft Academic Search

    P. Lienard; S. Lewy

    1975-01-01

    Acoustic measurements in semi-infinite space, near a nonabsorbing surface such as the ground, and in anechoic chambers which cannot be perfectly absorbing, necessarily lead to errors. For measurements of extended and point sources, near a flat surface, and in an anechoic surface, the deviation in decibels is computed with respect to sound pressure measured in the free field.

  7. THE PERFORMANCE OF ANECHOIC ROOMS

    Microsoft Academic Search

    F John DAVY

    Measurements of the frequency response of a prototype microphone turbulence screen in an anechoic room showed greater than expected ripple. Investigations showed that this was due to the residual reflections from the anechoic lining. Since it is necessary to reduce the effects of inverse square law over the 400 mm length of the microphone turbulence screen slit, the receiver could

  8. Electromagnetic Radiation (EMR) coupling to complex systems : aperture coupling into canonical cavities in reverberant and anechoic environments and model validation.

    SciTech Connect

    Charley, Dawna R.; Higgins, Matthew B.

    2007-12-01

    Mode-stirred chamber and anechoic chamber measurements were made on two sets of canonical test objects (cylindrical and rectangular) with varying numbers of thin slot apertures. The shielding effectiveness was compared to determine the level of correction needed to compensate the mode-stirred data to levels commensurate with anechoic data from the same test object.

  9. Anechoic Chamber o Echoless Room, existing equipment

    E-print Network

    Saskatchewan, University of

    M Nanotechnology Wii remote hacks o http://www.ted.com/talks/lang/eng/ johnny_lee_demos_wii_remote_hacks by Science Fiction o Flip phones o Geostationary satellite o Etc. (a Google search brings up lots) Gel

  10. Meeting the NSA Requirement for CISPR 16-1-4 in a MIL-STD-461E Type Semi Anechoic Room

    Microsoft Academic Search

    F. Ustuner; C. Cosar; E. Demirel; A. Dagdeviren

    2007-01-01

    The radiated emissions measurements require different types of anechoic chambers for civil and military EMC standards. An anechoic chamber constructed according to the requirements of MIL-STD-46IE may not meet the requirements in CISPR 16-1-4. Instead of constructing a new semi anechoic room (SAR), an investigation on the possible use of a SAR originally constructed for MIL-STD-461E tests to perform the

  11. Static and wind tunnel near-field/far-field jet noise measurements from model scale single-flow base line and suppressor nozzles. Summary report. [conducted in the Boeing large anechoic test chamber and the NASA-Ames 40by 80-foot wind tunnel

    NASA Technical Reports Server (NTRS)

    Jaeck, C. L.

    1977-01-01

    A test program was conducted in the Boeing large anechoic test chamber and the NASA-Ames 40- by 80-foot wind tunnel to study the near- and far-field jet noise characteristics of six baseline and suppressor nozzles. Static and wind-on noise source locations were determined. A technique for extrapolating near field jet noise measurements into the far field was established. It was determined if flight effects measured in the near field are the same as those in the far field. The flight effects on the jet noise levels of the baseline and suppressor nozzles were determined. Test models included a 15.24-cm round convergent nozzle, an annular nozzle with and without ejector, a 20-lobe nozzle with and without ejector, and a 57-tube nozzle with lined ejector. The static free-field test in the anechoic chamber covered nozzle pressure ratios from 1.44 to 2.25 and jet velocities from 412 to 594 m/s at a total temperature of 844 K. The wind tunnel flight effects test repeated these nozzle test conditions with ambient velocities of 0 to 92 m/s.

  12. Calibration of an anechoic room

    Microsoft Academic Search

    K. O. Ballagh

    1986-01-01

    A recently completed anechoic room with 100 m3 working space and 1 m long foam plastic wedges is described. An improved method of measuring the deviations from an ideal free field was used to calibrate the room. Within a 0.5 m radius of the source, the maximum deviation from a free field is 0.14 dB.

  13. University of Missouri–Rolla cloud simulation facility: Proto II chamber

    Microsoft Academic Search

    Daniel R. White; James L. Kassner; John C. Carstens; Donald E. Hagen; John L. Schmitt; Darryl J. Alofs; Alfred R. Hopkins; Max B. Trueblood; Max W. Alcorn; William L. Walker

    1987-01-01

    The Graduate Center for Cloud Physics Research at UMR has developed a cloud simulation facility to study phenomena occurring in terrestrial clouds and fogs. The facility consists of a pair of precision cooled-wall expansion chambers along with extensive supporting equipment. The smaller of these chambers, described in this article, is fully operational, and is capable of simulating a broad range

  14. Trade study comparing specimen chamber servicing methods for the Space Station Centrifuge Facility

    NASA Technical Reports Server (NTRS)

    Calvisi, Michael L.; Sun, Sidney C.

    1991-01-01

    The Specimen Chamber Service Unit, a component of the Space Station Centrifuge Facility, must provide a clean enclosure on a continuing basis for the facility's plant, rodent and primate specimens. The specimen chambers can become soiled and can require periodic servicing to maintain a clean environment for the specimens. Two methods of servicing the specimen chambers are discussed: washing the chambers with an on-board washer, or disposing of the soiled chambers and replacing them with clean ones. Many of these issues are addressed by developing several servicing options, using either cleaning or replacement as the method of providing clean specimen chambers, and then evaluating each option according to a set of established quantitative and qualitative criteria. Disposing and replacing the Specimen Chambers is preferable to washing them.

  15. The Kevlar-walled anechoic wind tunnel

    NASA Astrophysics Data System (ADS)

    Devenport, William J.; Burdisso, Ricardo A.; Borgoltz, Aurelien; Ravetta, Patricio A.; Barone, Matthew F.; Brown, Kenneth A.; Morton, Michael A.

    2013-08-01

    The aerodynamic and acoustic performance of an anechoic wind tunnel test section with walls made from thin Kevlar cloth have been measured and analyzed. The Kevlar test section offers some advantages over a conventional free-jet arrangement. The cloth contains the bulk of the flow but permits the transmission of sound with little loss. The containment results in smaller far-field aerodynamic corrections meaning that larger models can be tested at higher Reynolds numbers. The containment also eliminates the need for a jet catcher and allows for a much longer test section. Model-generated noise is thus more easily separated from facility background using beamforming. Measurements and analysis of acoustic and aerodynamic corrections for a Kevlar-walled test section are presented and discussed, along with benchmark trailing edge noise measurements.

  16. Evaluating the lining of anechoic room

    Microsoft Academic Search

    J. L. Davy

    1989-01-01

    This paper reports the evaluation of a method for measuring the pressure reflection factor of an anechoic room lining in situ, proposed by Kuttruff and Bruchmuller. In this method, a microphone and a sound source are mounted at a fixed distance and orientation to each other, on a turntable, which is rotated in the anechoic room. The variations in sound

  17. The crop growth research chamber: A ground-based facility for CELSS research

    NASA Technical Reports Server (NTRS)

    Bubenheim, David L.

    1990-01-01

    A ground based facility for the study of plant growth and development under stringently controlled environments is being developed by the Closed Ecological Life Support System (CELSS) program at the Ames Research Center. Several Crop Growth Research Chambers (CGRC) and laboratory support equipment provide the core of this facility. The CGRC is a closed (sealed) system with a separate recirculating atmosphere and nutrient delivery systems. The atmospheric environment, hydroponic environment, systems controls, and data acquisition are discussed.

  18. Analysis of electromagnetic pulse (EMP) measurements in the National Ignition Facility's target bay and chamber

    NASA Astrophysics Data System (ADS)

    Brown, C. G.; Clancy, T. J.; Eder, D. C.; Ferguson, W.; Throop, A. L.

    2013-11-01

    From May 2009 to the present we have recorded electromagnetic pulse (EMP) strength and spectrum (100 MHz - 5 GHz) in the target bay and chamber of the National Ignition Facility (NIF). The dependence of EMP strength and frequency spectrum on target type and laser energy is discussed. The largest EMP measured was for relatively low-energy, short-pulse (100 ps) flat targets.

  19. Adaptive separation of acoustic sources for anechoic conditions

    E-print Network

    Anemüller, Jörn

    of sources in rooms can be approximated as a superposition under anechoic conditions. Specifically, attenAdaptive separation of acoustic sources for anechoic conditions: A constrained frequency domain and experimentally, including sepa- ration of a moving and a fixed speaker in a recorded real anechoic environment

  20. The Crop Growth Research Chamber - A ground-based facility for CELSS research

    NASA Technical Reports Server (NTRS)

    Bubenheim, David L.; Luna, Phil M.; Wagenbach, Kimberly M.; Haslerud, Mark; Straight, Christian L.

    1989-01-01

    Crop Growth Research Chambers (CGRCs) are being developed as CELSS research facilities for the NASA/Ames Research Center. The history of the CGRC project is reviewed, noting the applications of CGRC research for the development of the Space Station. The CGRCs are designed for CELSS research and development, system control and integration, and flight hardware design and experimentation. The atmospheric and hydroponic environments of the CGRC system are described and the science requirements for CGRC environmental control are listed.

  1. A Concept for a Low Pressure Noble Gas Fill Intervention in the IFE Fusion Test Facility (FTF) Target Chamber

    Microsoft Academic Search

    C. A. Gentile; W. R. Blanchard; T. A. Kozub; M. Aristova; C. McGahan; S. Natta; K. Pagdon; J. Zelenty

    2010-01-01

    An engineering evaluation has been initiated to investigate conceptual engineering methods for implementing a viable gas shield strategy in the Fusion Test Facility (FTF) target chamber. The employment of a low pressure noble gas in the target chamber to thermalize energetic helium ions prior to interaction with the wall could dramatically increase the useful life of the first wall in

  2. Acoustic-RF anechoic chamber construction and evaluation

    Microsoft Academic Search

    G. Garner; J. Wilkerson; M. M. Skeen; D. F. Patrick; R. D. Hodges; R. D. Schimizzi; S. R. Vora; Zhiping Feng; K. G. Gard; M. B. Steer

    2008-01-01

    The use of sound as a means to gather information about our environment has been developed with limited scope over the past several decades. The primary application of this technology has been ultrasound and ultrasonic ranging. Recent developments in nonlinear acoustics have proven that two-tone measurements and directional high frequency parametric arrays can extract much more information about the size,

  3. New acoustic test facility at Georgia Tech

    NASA Astrophysics Data System (ADS)

    Biesel, Van; Cunefare, Kenneth

    2002-11-01

    Georgia Tech's Integrated Acoustics Laboratory (IAL) is a state of the art research facility dedicated to the study of acoustics and vibration. The centerpiece of the laboratory is a 24 ft x24 ft x20 ft full anechoic chamber, which has been in operation since 1998. The IAL is currently expanding to include a reverberation room and hemi-anechoic chamber, designed and built by Acoustic Systems. These two chambers will be joined by an 8 ft x8 ft transmission loss opening, allowing for a detailed measurement and analysis of complex barriers. Both chambers will accommodate vehicles and similarly large structures. The reverberation room will have adequate volume for standardized absorption measurements. Each chamber will be equipped with dedicated multichannel data acquisition systems and instrumentation for the support of simultaneous research in all areas of the laboratory. The new test chambers are funded by a grant from the Ford Motor Company and are planned to be completed and fully functional by 1 January 2003.

  4. A time domain spherical near-field measurement facility for UWB antennas employing a hardware gating technique

    Microsoft Academic Search

    M. D. Blech; M. M. Leibfritz; R. Hellinger; D. Geier; F. A. Maier; A. M. Pietsch; T. F. Eibert

    2010-01-01

    A spherical near-field antenna measurement facility employing a time domain hardware gating technique is presented. On-off keyed sinusoidal impulses are used as stimuli requiring wideband antennas with a bandwidth in excess of 400 MHz. The received signal is evaluated in the time interval after reaching the steady state and before multipath components arising in the non-ideal anechoic chamber distort the

  5. Comparison of Indiana University Cyclotron Facility Faraday cup proton dosimetry with radiochromic films, a calorimeter, and a calibrated ion chamber

    Microsoft Academic Search

    A. Z. Jones; C. D. Bloch; E. R. Hall; R. Hashemian; S. B. Klein; B. von Przewoski; K. M. Murray; C. C. Foster

    1999-01-01

    The accuracy and utility of the dosimetry system used for radiation effects research with high energy protons at the Indiana University Cyclotron Facility, IUCF, has been confirmed by comparison with an independently calibrated Markus ion chamber, a Schulz water calorimeter and GAFCHROMICTM films

  6. Comparison of Indiana University Cyclotron Facility Faraday cup proton dosimetry with radiochromic films, a calorimeter, and a calibrated ion chamber

    SciTech Connect

    Jones, A.Z.; Bloch, C.D.; Hall, E.R.; Hashemian, R.; Klein, S.B.; Przewoski, B. von; Murray, K.M.; Foster, C.C.

    1999-12-01

    The accuracy and utility of the dosimetry system used for radiation effects research with high energy protons at the Indiana University Cyclotron Facility, IUCF, has been confirmed by comparison with an independently calibrated Markus ion chamber, a Schulz water calorimeter and GAFCHROMIC{trademark} films.

  7. Design features for free-field qualification of a new semi-anechoic room, and qualification performance

    NASA Astrophysics Data System (ADS)

    Cunefare, Kenneth A.; Biesel, Van; Holdhusen, Mark; Shoemaker, Austin

    2003-10-01

    Precision qualification of a semi-anechoic room requires careful attention to the sound source and traversing method. Prior work, with test sources mounted above the reflecting floor of such a room, has indicated the potential for image source problems in the resulting field. To address such shortcomings, the new Georgia Tech semi-anechoic room was constructed with a recessed enclosure in the center of the floor. This enclosure permits the implementation of test sources coincident with the reflecting plane of the floor. In addition, prior work in an anechoic room has indicated the inadequacy of qualification traverses implemented at large spacings. To address this issue, hard-points were designed and implemented within the room to permit installation of traverse cables extending radially from the in-floor source enclosure out to the walls and corners. These traverse cables are an integral component of a custom continuous traverse system. The design features of the chamber which facilitate chamber qualification will be presented, along with the broadband and pure tone results of the qualification performed on the chamber.

  8. The anechoic and reverberant rooms at the Building Research Station

    Microsoft Academic Search

    P. H. Parkin; E. F. Stacy

    1971-01-01

    The anechoic and reverberant rooms at the Building Research Station are described, attention being concentrated on the design details. The behaviour of the laboratories since they were completed is briefly discussed.

  9. Ventilation characterization of the Consumer Product Safety Commission combustion test chamber facility. Final report

    Microsoft Academic Search

    Dols

    1990-01-01

    The Consumer Product Safety Commission (CPSC) is evaluating pollutant emissions from kerosene and methane heaters using a test chamber. Under an interagency agreement with CPSC, the Indoor Air Quality and Ventilation Group of the National Institute of Standards and Technology (NIST) measured the air exchange rate of the chamber under various ventilation system operating conditions, the extent of air mixing

  10. Adaptive separation of acoustic sources for anechoic conditions: A constrained frequency

    E-print Network

    of sources in rooms can be approximated as a superposition under anechoic conditions. SpecificallyAdaptive separation of acoustic sources for anechoic conditions: A constrained frequency domain and experimentally, including separation of a moving and a fixed speaker in a recorded real anechoic environment

  11. Mars and Lunar Vacuum Chamber Testing Facilities and Vacuum Rated Drill Systems

    Microsoft Academic Search

    K. Zacny; G. Paulsen; J. Craft; M. Maksymuk; C. Santoro; J. Wilson

    2009-01-01

    Martian and Lunar low pressure and vacuum conditions, respectively, greatly affect the performance of the drilling mechanics and drill hardware. For this reason, it is imperative to test planetary sampling and coring drills under these specific environments. Honeybee Robotics acquired an 11ft vacuum chamber that is currently being used to test drills to 1m depth and more. A separate cooling

  12. Engine noise testing in an economical ''semi'' anechoic room

    Microsoft Academic Search

    R. Gaspar; Z. Reif; K. Sridhar

    1978-01-01

    A ''semi'' anechoic room design has been proposed and constructed from readily available, inexpensive construction materials. To demonstrate its feasibility, noise testing was conducted using a rotary engine as the noise source. The results of the testing indicated that the design is functional since free field conditions exist. This condition was proven to exist for at least one angular position

  13. Flat-walled multilayered anechoic linings: Optimization and application

    NASA Astrophysics Data System (ADS)

    Xu, Jingfeng; Buchholz, Jörg M.; Fricke, Fergus R.

    2005-11-01

    The concept of flat-walled multilayered absorbent linings for anechoic rooms was proposed three decades ago. Flat-walled linings have the advantage of being less complicated and, hence, less costly to manufacture and install than the individual units such as wedges. However, there are difficulties in optimizing the design of such absorbent linings. In the present work, the design of a flat-walled multilayered anechoic lining that targeted a 250 Hz cut-off frequency and a 300 mm maximum lining thickness was first optimized using an evolutionary algorithm. Sixteen of the most commonly used commercial fibrous building insulation materials available in Australia were investigated and fourteen design options (i.e., material combinations) were found by the evolutionary algorithm. These options were then evaluated in accordance with their costs and measured acoustic absorption performances. Finally, the completed anechoic room, where the optimized design was applied, was qualified and the results showed that a large percentage (75%-85%) of the distance between the sound source and the room boundaries, on the traverses made, were anechoic.

  14. A Concept for a Low Pressure Noble Gas Fill Intervention in the IFE Fusion Test Facility (FTF) Target Chamber

    SciTech Connect

    Gentile, C. A.; Blanchard, W. R.; Kozub, T. A.; Aristova, M.; McGahan, C.; Natta, S.; Pagdon, K.; Zelenty, J.

    2010-01-14

    An engineering evaluation has been initiated to investigate conceptual engineering methods for implementing a viable gas shield strategy in the Fusion Test Facility (FTF) target chamber. The employment of a low pressure noble gas in the target chamber to thermalize energetic helium ions prior to interaction with the wall could dramatically increase the useful life of the first wall in the FTF reactor1. For the purpose of providing flexibility, two target chamber configurations are addressed: a five meter radius sphere and a ten meter radius sphere. Experimental studies at Nike have indicated that a low pressure, ambient gas resident in the target chamber during laser pulsing does not appear to impair the ability of laser light from illuminating targets2. In addition, current investigations into delivering, maintaining, and processing low pressure gas appear to be viable with slight modification to current pumping and plasma exhaust processing technologies3,4. Employment of a gas fill solution for protecting the dry wall target chamber in the FTF may reduce, or possibly eliminate the need for other attenuating technologies designed for keeping He ions from implanting in first wall structures and components. The gas fill concept appears to provide an effective means of extending the life of the first wall while employing mostly commercial off the shelf (COTS) technologies. Although a gas fill configuration may provide a methodology for attenuating damage inflicted on chamber surfaces, issues associated with target injection need to be further analyzed to ensure that the gas fill concept is viable in the integrated FTF design5. In the proposed system, the ambient noble gas is heated via the energetic helium ions produced by target detonation. The gas is subsequently cooled by the chamber wall to approximately 800oC, removed from the chamber, and processed by the chamber gas processing system (CGPS). In an optimized scenario of the above stated concept, the chamber wall acts as the primary heat exchanger. During removal, gas is pumped through the laser ports by turbo molecular-drag pumps (TM-DP). For the purpose of reducing organic based lubricants and seals, a magnetically levitated TM-DP is being investigated with pump manufacturers. Currently, magnetically levitated turbo molecular pumps are commercially available. The pumps will be exposed to thermal loads and ionizing radiation (tritium, Ar-41, post detonation neutrons). Although the TM-DP's will be subjected to these various radiations, current designs for similar pumping devices have been hardened and have the ability of locating control electronics in remote radiation shielded enclosures4. The radiation hardened TM-DP's will be 5 required to operate with minimal maintenance for periods of up to 18 continuous months. As part of this initial investigation for developing a conceptual engineering strategy for a gas fill solution, commercial suppliers of low pressure gas pumping systems have been contacted and engaged in this evaluation. Current technology in the area of mechanical pumping systems indicates that the development of a robust pumping system to meet the requirements of the FTF gas fill concept is within the limits of COTS equipment3,4.

  15. Tests on an 8\\/100 scale model for the definition of the convergent and collector of CEPRA 19 \\/Anechoic open jet wind tunnel

    Microsoft Academic Search

    P. Rebuffet; A. Guedel

    1981-01-01

    An 8\\/100 scale model of the CEPRA 19 wind tunnel has been built in order to study and define the shape, size, and position of the jet collector in the tunnel's anechoic chamber. The jet collector is common to the 2 m and 3 m test sections, corresponding to free jet lengths of 5.42 D and 3.96 D, respectively. The

  16. A facility for the test of large-area muon chambers at high rates

    Microsoft Academic Search

    S. Agosteo; S. Altieri; G. Belli; A. Bonifas; V. Carabelli; L. Gatignon; N P Hessey; M. Maggi; J.-P Peigneux; H. Reithler; Marco Silari; P. Vitulo; M. Wegner

    2000-01-01

    Operation of large-area muon detectors at the future Large Hadron Collider (LHC) will be characterized by large sustained hit rates over the whole area, reaching the range of kHzcm?2. We describe a dedicated test zone built at CERN to test the performance and the aging of the muon chambers currently under development. A radioactive source delivers photons causing the sustained

  17. Decompression sickness rates for chamber personnel: case series from one facility.

    PubMed

    Brandt, Megan S; Morrison, Thomas O; Butler, William P

    2009-06-01

    During 2004, a case series of decompression sickness (DCS) meeting the definition of epidemic DCS was observed in the Shaw AFB Physiological Training Program. There were 10 cases of chamber-induced altitude DCS observed. Internal and external investigations focused on time, place, person, and environment. No temporal trend was observed. Chamber, masks, regulators, crew positions, and oxygen sources revealed no defects. Among the cases, mean age was 27 yr. Peak altitude in four cases was 35,000 ft and in the other six cases was 25,000 ft. Six had joint pain, one skin symptoms, and three neurological findings. Four were treated with 100% ground-level oxygen and six with hyperbaric oxygen. Four were students and six were inside observers (IO). Four were women and six men. In the IO, where four of the six were women, no gender effect was seen. Examining the IO monthly exposure load (exposures per month) against DCS suggested a dose-response relationship. This relationship held true when 4 yr of Shaw AFB IO data was studied. Indeed, Poisson regression analysis demonstrated a statistically significant 2.1-fold rise in DCS risk with each monthly exposure. Consequently, the number of exposures per month may need to be considered when devising IO schedules. PMID:19522370

  18. Mars and Lunar Vacuum Chamber Testing Facilities and Vacuum Rated Drill Systems

    NASA Astrophysics Data System (ADS)

    Zacny, K.; Paulsen, G.; Craft, J.; Maksymuk, M.; Santoro, C.; Wilson, J.

    2009-12-01

    Martian and Lunar low pressure and vacuum conditions, respectively, greatly affect the performance of the drilling mechanics and drill hardware. For this reason, it is imperative to test planetary sampling and coring drills under these specific environments. Honeybee Robotics acquired an 11ft vacuum chamber that is currently being used to test drills to 1m depth and more. A separate cooling system is used to maintain low temperature of planetary analog formations such as ice, soil, icy-soils, and rocks. The low temperature increases the strength of these formations and in turn reduces drilling efficiency. The chamber also has a numerous feed troughs that can be used to transfer thermal data from thermocouples embedded inside the drilled sample, and the drill bits. The thermal data is useful to determine the temperature the sample reaches during the drilling process. The drill systems include rotary, rotary-percussive, and rotary-sonic. The latter two, in particular, offer superior performance in hard formations due to impacts and/or vibrations that enhance penetration rate. All the drill systems are vacuum rated and hence can be used as test platforms for vacuum testing.

  19. Flat-walled multilayered anechoic linings: Optimization and application

    Microsoft Academic Search

    Jingfeng Xu; Jörg M. Buchholz; Fergus R. Fricke

    2005-01-01

    The concept of flat-walled multilayered absorbent linings for anechoic rooms was proposed three decades ago. Flat-walled linings have the advantage of being less complicated and, hence, less costly to manufacture and install than the individual units such as wedges. However, there are difficulties in optimizing the design of such absorbent linings. In the present work, the design of a flat-walled

  20. Venus Pressure Chamber: A Small Testing Facility Available to the Community

    NASA Technical Reports Server (NTRS)

    Johnson, Natasha M.; Wegel, D. C.

    2011-01-01

    Venus is an inhospitable planet where the surface mean. temperature is approximately 740K and the global mean pressure is approximately 95 bars. The atmosphere is comprised mostly of CO2 (approximately 96.5%) and N2 (approximately3.5%) with trace amounts of CO and other reactive gases. Although Venus is very similar in size and mass with the Earth and is Earth's nearest planetary neighbor, it has not received many visitors from Earth, especially those that can land on the surface. The challenge most often cited for this scarcity of surface probes is the workability/survivability of instruments and equipment in Venus' harsh environment. In order to overcome this obstacle, a small pressure chamber has been acquired for use by the scientific community. It is housed at Goddard Space. Flight Center in Maryland and is available to the community for testing of small flight components, instruments and short-term experiments that require high temperatures and pressures.

  1. Anechoic wind tunnel study of turbulence effects on wind turbine broadband noise

    NASA Technical Reports Server (NTRS)

    Loyd, B.; Harris, W. L.

    1995-01-01

    This paper describes recent results obtained at MIT on the experimental and theoretical modelling of aerodynamic broadband noise generated by a downwind rotor horizontal axis wind turbine. The aerodynamic broadband noise generated by the wind turbine rotor is attributed to the interaction of ingested turbulence with the rotor blades. The turbulence was generated in the MIT anechoic wind tunnel facility with the aid of biplanar grids of various sizes. The spectra and the intensity of the aerodynamic broadband noise have been studied as a function of parameters which characterize the turbulence and of wind turbine performance parameters. Specifically, the longitudinal integral scale of turbulence, the size scale of turbulence, the number of turbine blades, and free stream velocity were varied. Simultaneous measurements of acoustic and turbulence signals were made. The sound pressure level was found to vary directly with the integral scale of the ingested turbulence but not with its intensity level. A theoretical model based on unsteady aerodynamics is proposed.

  2. Archiving Quality Control Tests in the PHENIX Resistive Plate Chamber Assembly Facility

    NASA Astrophysics Data System (ADS)

    Andrews, Keller

    2009-10-01

    The PHENIX collaboration at RHIC studies polarized proton-proton collisions to better understand the spin structure of the proton. PHENIX is in the process of upgrading the muon trigger to improve our capabilities of selecting the muons from the decay of W-bosons which are produced more readily at a high transverse momentum than other muon sources. By triggering on single, high transverse momentum muons, new observations on the spin asymmetries of a proton can be obtained. The trigger upgrade will consist of four stations of Resistive Plate Chambers (RPCs), with stations on each side of the interaction region. Each RPC consists of two Bakelite gas gaps, a copper signal plane, an aluminum case, and several layers of mylar and copper. With all of these parts comes the need to archive the manufacturing and quality assurance information along with test results performed on them. This information is kept in a Postgresql Database in the RPC factory and is maintained, modified, and read out through several PHP web pages. A new output page has been produced that will make all of this information much more accessible. This poster will focus on what data is archived, how it is stored, and how it can be easily retrieved and put to use.

  3. Spatial unmasking of nearby speech sources in a simulated anechoic environment

    E-print Network

    Shinn-Cunningham, Barbara G.

    Spatial unmasking of nearby speech sources in a simulated anechoic environment Barbara G. Shinn Engineering, Boston University, 677 Beacon St., Room 311, Boston, Massachusetts 02215 Jason Schickler Boston

  4. DATE OF REQUEST: NVLAP LAB CODE: ECT APPLICATION ADDENDUM #2 (2008-09-12) PAGE 1 OF 3

    E-print Network

    Facility Name: Anechoic chamber Room A Facility Type: Semi-anechoic chamber Test Types* Test Methods Room B Facility Type: Semi-anechoic chamber Test Types* Test Methods Reference Standards Test Condition/EN55022 FCC method 47CFR/Part 15 measuring distance: 3 m Facility Name: Shielded Room A Facility Type

  5. Simulation of flight-type engine fan noise in the NASA-Lewis 9 x 15 anechoic wind tunnel

    NASA Technical Reports Server (NTRS)

    Heidmann, M. F.; Dietrich, D. A.

    1976-01-01

    A major problem in the measurement of aircraft engine fan noise is the difficulty of simulating, in a ground-based facility, the noise that occurs during flight. Flight-type noise as contrasted to the usual ground-static test noise exhibits substantial reductions in both (1) the time unsteadiness of tone noise and (2) the mean level of tones calculated to be nonpropagating or cut-off. A model fan designed with cut-off of the fundamental tone was acoustically tested in the anechoic wind tunnel under both static and tunnel flow conditions. The properties that characterize flight-type noise were progressively simulated with increasing tunnel flow. The distinctly lobed directivity pattern of propagating rotor/stator interaction modes was also observed. The results imply that the excess noise attributed to the ingestion of the flow disturbances that prevail near most static test facilities was substantially reduced with tunnel flow. The anechoic wind tunnel appears to be a useful facility for applied research on aircraft engine fan noise under conditions of simulated flight.

  6. Intercomparison of active, passive and continuous instruments for radon and radon progeny measurements in the EML chamber and test facility

    SciTech Connect

    George, A.C.; Knutson, E.O.; Tu, K.W.; Fisenne, I.M.

    1995-12-01

    The results from the May 1995 Intercomparison of Active, Passive and Continuous Instruments for Radon and Radon Progeny Measurement conducted in the EML radon exposure and test facility are presented. Represented were 13 participants that measure radon with open faced and diffusion barrier activated carbon collectors, 10 with nuclear alpha track detectors, 9 with short-term and long-term electret/ionization chambers, and 13 with active and passive commercial electronic continuous monitors. For radon progeny, there were four participants that came in person to take part in the grab sampling methodology for measuring individual radon progeny and the potential alpha energy concentration (PAEC). There were 11 participants with continuous and integrating commercial electronic instruments that are used for measuring the PAEC. The results indicate that all the tested instruments that measure radon fulfill their intended purpose. All instruments and methods used for grab sampling for radon progeny did very well. However, most of the continuous and integrating electronic instruments used for measuring the PAEC or working level appear to underestimate the potential risk from radon progeny when the concentration of particles onto which the radon progeny are attached is <5,000 cm{sup -3}.

  7. Generation of Free Space Radiation Patterns From Non-Anechoic Measurements Using Chebyshev Polynomials

    Microsoft Academic Search

    Zhou Du; Jung Ick Moon; Soon-Soo Oh; Jinhwan Koh; Tapan Kumar Sarkar

    2010-01-01

    Generally, antenna radiation patterns are measured in an anechoic condition so that the presence of undesired reflections does not skew the final measurements. The objective of this communication is to search for methodologies which can extract meaningful approximate results from non-anechoic measurements. In other words, how to process the reflection contaminated data and extract valuable information when one does not

  8. Evaluating semi-anechoic rooms using an accurate and ultra-repeatable source

    Microsoft Academic Search

    B. Archambeault; P. Valentino; E. Schumann

    2001-01-01

    Semi-anechoic rooms are very popular for making commercial EMI emissions measurements. They allow measurements in a RF quiet environment, so that low level fields may be measured without masking by ambient signals. The absorber material on the walls prevent reflections etc. which would change the value of the received signal level. Standard test procedures exist to test the anechoic room

  9. Anechoic Chamber test of the Electromagnetic Measurement System ground test unit

    Microsoft Academic Search

    L. E. Stevenson; L. D. Scott; E. T. Oakes

    1987-01-01

    The Electromagnetic Measurement System (EMMS) will acquire data on electromagnetic (EM) environments at key weapon locations on various aircraft certified for nuclear weapons. The high-frequency ground unit of the EMMS consists of an instrumented B61 bomb case that will measure (with current probes) the localized current density resulting from an applied EM field. For this portion of the EMMS, the

  10. Comparison of particle velocity and sound pressure measurements in anechoic and medfly bioassay chambers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many insects without tympanal ears do not perceive the pressure component of sound, but instead have movement receptors (usually small hairs on body or antennae) that are sensitive to sound particle velocity -- oscillations of air particles in the sound field. In our laboratory, efforts to develop...

  11. Prelaunch Estimation of Radiometric Resolution and Stability of SMOS Zero-Baseline Radiometer in Anechoic Chamber

    Microsoft Academic Search

    Andreas Colliander; Manuel Martin-Neira; Josep Closa; Javier Benito

    2010-01-01

    The purpose of the Soil Moisture and Ocean Salinity (SMOS) mission is to measure soil moisture and sea surface salinity (SSS). The measurement of SSS using microwave radiometry requires a very sensitive instrument. In SMOS, the image is formed using the interferometric technique complemented by the average brightness temperature, or zero baseline, to set the absolute level of the image.

  12. NSA and resonance in a semi-anechoic chamber in low frequency

    Microsoft Academic Search

    Liu Chen; Wen Yinghong; Zhang Lincheng

    1997-01-01

    As a result of the continuing growth of high speed electronic systems and equipment in the world, EMI (electromagnetic interference) is becoming a big problem. Specifications for the purpose of imposing maximum acceptable levels of noise that can be radiated from electronic systems and equipment have been published. Almost all the electronic products in the world should be tested to

  13. Using voltage-driven model to correlate GTEM cell and anechoic chamber measurement

    Microsoft Academic Search

    Bo Zhao; Min Zhao; Daosheng Chen

    2012-01-01

    To improve the accuracy of the GTEM cell applied in radiated EMI measurement, an EMI noise extraction model and the error compensation method based on variance analysis are proposed. High moments were employed to compare the similarity of the two test curves between the GTEM cell after calibration and the standard test. The experimental results for a PCB using the

  14. Measurements and simulations of a Doppler radiometer in an anechoic chamber

    Microsoft Academic Search

    Daniel M. Fernandez; Adriano Camps

    2004-01-01

    The microwave Doppler radiometer can potentially allow satellite-based radiometers to operate with improved resolution than is currently available (30-40 km) and with a much-reduced number of sensing antennas (as few as 3). Such a radiometer relies on the motion of the satellite to create an image based on the cross-correlations of focused signals collected from multiple receivers. The angular resolution

  15. Comparison of particle velocity and sound pressure measurements in anechoic and medfly bioassay chambers

    Microsoft Academic Search

    J. B. Anderson; R. W. Mankin

    Many insects without tympanal ears do not perceive the pressure component of sound, but instead have movement receptors (usually small hairs on body or antennae) that are sensitive to sound particle velocity -- oscillations of air particles in the sound field. In our laboratory, efforts to develop an acoustic trap for mate-seeking female medflies have centered on utilizing the particle

  16. Development and tests of interferometry facility in 6-m diameter radiometer thermal vacuum chamber in Tsukuba Space Center

    Microsoft Academic Search

    Masahiro Suganuma; Haruyoshi Katayama; Masataka Naitoh; Tadashi Imai; Masashi Miyamoto; Kenta Maruyama; Hidehiro Kaneda; Yoshio Tange; Takao Nakagawa

    2010-01-01

    We present a test of optical metrology for 800-mm spaceborne optics in the 6-m radiometer thermal vacuum chamber at JAXA's Tsukuba Space Center of JAXA. Under the framework of the JAXA's large-optics study program for astronomy and Earth observations, we developed a test bench for interferometric metrology of large optics with an auto-collimation method in the chamber. The optical system

  17. Development of the mini-ionization chamber for high-dose real-time monitoring inside a gamma irradiation facility

    Microsoft Academic Search

    Ary de A. Rodrigues; Jose M. Vieira; Margarida M. Hamada

    2003-01-01

    A cylindrical ionization chamber of 0.9 cm3 has been developed for high-doses real-time monitoring during the sample irradiation at a static position in a 60Co gamma industrial plant, with about 25.9 PBq (700 kCi). Nitrogen gas at pressure of 1 bar was utilized to fill the ionization chamber for which an appropriate configuration was determined, to be used as a

  18. Flow chamber

    DOEpatents

    Morozov, Victor (Manassas, VA)

    2011-01-18

    A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.

  19. Measurement of above 1 GHz EMC antennas in a fully anechoic room

    Microsoft Academic Search

    Yu Ji; Desmond C. Arthur; Frank M. Warner

    2008-01-01

    This paper describes a method of measuring the free-space antenna factors of above 1 GHz EMC antennas in a fully anechoic room (FAR) which is validated by comparison with an open area test site (OATS).

  20. Ultra-light duct for an anechoic wind tunnel

    NASA Technical Reports Server (NTRS)

    Lambourion, J.; Lewy, S.; Papirnyk, O.; Rahier, G.; Remandet, J.-N.

    1989-01-01

    A tunnel ultra-light (or TUL) is a duct composed of acoustically transparent cloth designed to transform an open-jet wind tunnel into a closed-jet wind tunnel. This concept is of interest (a priori) for anechoic wind tunnels because it improves the aerodynamic quality without hindering the measurement of sound in the far field. A full scale device designed for the 3 m diameter test section of CEPRA 19 was described. The apparatus installation did not develop any significant problems, and the mechanical support turned out to be excellent. Aerodynamic and acoustic tests are discussed. Certain imperfections in the installation as tested - instabilities above 25 m/s and acceptable cloth transmission up to 4kHz were revealed. The system as tested could eventually be used in certain applications, for example, in ground based transport. However, the concept of TUL must be developed further to arrive at a reliable mechanism for use in a large number of applications.

  1. Tests on an 8/100 scale model for the definition of the convergent and collector of CEPRA 19 /Anechoic open jet wind tunnel/

    NASA Astrophysics Data System (ADS)

    Rebuffet, P.; Guedel, A.

    1981-10-01

    An 8/100 scale model of the CEPRA 19 wind tunnel has been built in order to study and define the shape, size, and position of the jet collector in the tunnel's anechoic chamber. The jet collector is common to the 2 m and 3 m test sections, corresponding to free jet lengths of 5.42 D and 3.96 D, respectively. The overall background noise was measured, as well as aerodynamic characteristics: the velocity distribution in the jet core, the extent of mixing layers, and the reverse flow in the chamber. A resonance frequency observed at some velocities for some test frequencies was explained by an excitation of the architectural modes of the cavity caused by an edgetone mechanism between the convergent nozzle and the collector. Summary measurements performed in the wind tunnel were in good agreement with the predictions deduced from the scaled-down tests.

  2. Learning to judge distance of nearby sounds in reverberant and anechoic environments Norbert Kopco1,2

    E-print Network

    Shinn-Cunningham, Barbara G.

    Learning to judge distance of nearby sounds in reverberant and anechoic environments Norbert Kopco1 Introduction Some recent studies of auditory distance perception in real rooms [1,2] report that listeners improvement is not observed in an anechoic environment [3], suggesting that listeners learn (through

  3. A new laboratory facility to study gas-aerosol-cloud interactions in a turbulent environment: The ? Chamber

    NASA Astrophysics Data System (ADS)

    Niedermeier, Dennis; Cantrell, Will; Chang, Kelken; Ciochetto, David; Bench, Jim; Shaw, Raymond

    2015-04-01

    A detailed understanding of interactions of aerosols, cloud droplets/ice crystals, and trace gases within the turbulent atmosphere is of prime importance for an accurate understanding of Earth's climate system. But despite extensive research activity during the last decades these interactions are still poorly understood and ill quantified. For example: Every cloud droplet in Earth's atmosphere (~1025) was catalyzed by a preexisting aerosol particle. While every cloud droplet began as an aerosol particle, not every aerosol particle becomes a cloud droplet. The particle to droplet transformation, known as activation, requires that the particle be exposed to some critical concentration of water vapor, which differs for different combinations of particle size and chemical composition. Similarly, the formation of ice particles in the atmosphere is often catalyzed by aerosol particles, either activated or not. Even in the simplest scenarios it is challenging to gain a full understanding of the aerosol activation and ice nucleation processes, but at least two other factors contribute greatly to the complexity observed in the atmosphere. First, aerosols and cloud particles are not static entities, but are continuously interacting with their chemical environment, and therefore changing in their properties. Second, clouds are ubiquitously turbulent, and therefore thermodynamic and compositional variables, such as water vapor or trace gas concentration, fluctuate in space and time. Indeed, the coupling between turbulence and microphysical processes is recognized as one of the major research challenges in cloud physics today. We have developed a multiphase, turbulent reaction chamber - called the ? Chamber because of the internal volume of 3.14 m3 (with cylindical wall installed) - designed to address the open issues outlined above. It is capable of pressures ranging from sea level to ~60 mbar, and can sustain temperatures of +55 to -55

  4. Virtual Anechoic Room An Useful Tool for EMI Pre-Compliance Testing

    Microsoft Academic Search

    J. Svacina; J. Drinovsky; R. Videnka

    2007-01-01

    The paper deals with principles of so-called virtual anechoic room, which presents an economical and accessible possibility of ambient signal elimination in open field test site (OFTS) EMI measurement. Some variants of easy and efficient EM ambient cancellation are described and some measurement examples are presented in the article. In general, the radiated and conducted EM measurement based on principle

  5. A fast automatic calibration system for a sound level meter in an anechoic room

    Microsoft Academic Search

    Yong Tae Kim; Yong Bong Lee; Moon Jae Jho

    2003-01-01

    A fast automatic calibration system for a sound level meter in an anechoic environment has been developed. The precise and fast generation of the constant frequency-independent acoustic pressure field and reduction of digital voltmeter readout to sound pressure level were achieved by a newly designed software algorithm, assuming the system linearity. The performance test justified the assumed linearity, and showed

  6. Measurement on an Active Phased Array Antenna on a Near-Field Range and an Anechoic Far-Field Chamber

    Microsoft Academic Search

    Wolfgang Haselwander; Manfred Uhlmann; Stefan Wustefeld; Markus Bock

    2001-01-01

    Active Phased Array Antennas especially for use in Radar Systems (e.g. Airborne Radars) have to be adjusted and tested very well before they can be operated in the Radar System. This Adjustment Process shall guarantee the Antenna Performance under all operating conditions. Therefore, the Active Phased Array Antenna is measured on a Near-Field Test Range to determine the Adjustment Corrections

  7. Modeling and Simulation of a Bird's-eye-Type Ferrite Electromagnetic Wave Absorber For an Anechoic Chamber

    Microsoft Academic Search

    Hyun Jin Yoon; Dong Il Kim

    2004-01-01

    The purpose of this study is to design and fabricate an electromagnetic (EM) wave absorber in order to achieve the wide-band characteristic. We proposed and modeled a bird's-eye-type EM wave absorber using the equivalent material constants method (EMCM), and we evaluated it through simulation using the finite difference time domain (FDTD) method. The numerical simulation showed that a bird's-eye-type periodic

  8. November 2012 Volume 7, Issue 8

    E-print Network

    Oklahoma, University of

    , prototype fabrication facilities, machine shop, two precision anechoic chambers, experimental observation deck, and a unique "Ideas Room" to foster collaboration and innovation. The RIL will be located just

  9. Performance of the high speed anechoic wind tunnel at Lyon University

    NASA Technical Reports Server (NTRS)

    Sunyach, M.; Brunel, B.; Comte-Bellot, G.

    1986-01-01

    The characteristics of the feed duct, the wind tunnel, and the experiments run in the convergent-divergent anechoic wind tunnel at Lyon University are described. The wind tunnel was designed to eliminate noise from the entrance of air or from flow interactions with the tunnel walls so that noise caused by the flow-test structure interactions can be studied. The channel contains 1 x 1 x 0.2 m glass and metal foil baffles spaced 0.2 m apart. The flow is forced by a 350 kW fan in the primary circuit, and a 110 kW blower in the secondary circuit. The primary circuit features a factor of four throat reductions, followed by a 1.6 reduction before the test section. Upstream and downstream sensors permit monitoring of the anechoic effectiveness of the channel. Other sensors allow modeling of the flow structures in the tunnel. The tunnel was used to examine turbulent boundary layers in flows up to 140 m/sec, tubulence-excited vibrations in walls, and the effects of laminar and turbulent flows on the appearance and locations of noise sources.

  10. Chamber B Thermal/Vacuum Chamber: User Test Planning Guide

    NASA Technical Reports Server (NTRS)

    Montz, Mike E.

    2012-01-01

    Test process, milestones and inputs are unknowns to first-time users of Chamber B. The User Test Planning Guide aids in establishing expectations for both NASA and non-NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their test engineering personnel in test planning and execution. Material covered includes a roadmap of the test process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, test article interfaces, and inputs necessary to define test scope, cost, and schedule are included as an appendix to the guide.

  11. Research and test facilities

    NASA Technical Reports Server (NTRS)

    1993-01-01

    A description is given of each of the following Langley research and test facilities: 0.3-Meter Transonic Cryogenic Tunnel, 7-by 10-Foot High Speed Tunnel, 8-Foot Transonic Pressure Tunnel, 13-Inch Magnetic Suspension & Balance System, 14-by 22-Foot Subsonic Tunnel, 16-Foot Transonic Tunnel, 16-by 24-Inch Water Tunnel, 20-Foot Vertical Spin Tunnel, 30-by 60-Foot Wind Tunnel, Advanced Civil Transport Simulator (ACTS), Advanced Technology Research Laboratory, Aerospace Controls Research Laboratory (ACRL), Aerothermal Loads Complex, Aircraft Landing Dynamics Facility (ALDF), Avionics Integration Research Laboratory, Basic Aerodynamics Research Tunnel (BART), Compact Range Test Facility, Differential Maneuvering Simulator (DMS), Enhanced/Synthetic Vision & Spatial Displays Laboratory, Experimental Test Range (ETR) Flight Research Facility, General Aviation Simulator (GAS), High Intensity Radiated Fields Facility, Human Engineering Methods Laboratory, Hypersonic Facilities Complex, Impact Dynamics Research Facility, Jet Noise Laboratory & Anechoic Jet Facility, Light Alloy Laboratory, Low Frequency Antenna Test Facility, Low Turbulence Pressure Tunnel, Mechanics of Metals Laboratory, National Transonic Facility (NTF), NDE Research Laboratory, Polymers & Composites Laboratory, Pyrotechnic Test Facility, Quiet Flow Facility, Robotics Facilities, Scientific Visualization System, Scramjet Test Complex, Space Materials Research Laboratory, Space Simulation & Environmental Test Complex, Structural Dynamics Research Laboratory, Structural Dynamics Test Beds, Structures & Materials Research Laboratory, Supersonic Low Disturbance Pilot Tunnel, Thermal Acoustic Fatigue Apparatus (TAFA), Transonic Dynamics Tunnel (TDT), Transport Systems Research Vehicle, Unitary Plan Wind Tunnel, and the Visual Motion Simulator (VMS).

  12. InterLaboratory Comparisons for Radiated Emissions Measurements in Compact, Fully-Anechoic, Rooms: a Proposed Simplified Protocol

    Microsoft Academic Search

    Carlo F. M. Carobbi; Marco Cati; Carlo Panconi; Luigi M. Millanta

    1 - Scope All radiated emission measurements for EMC applications suffer from some lack of reproducibility, with presumably less favourable figures when more economic solutions are adopted, which is the case for small- size rooms. The so called Compact Fully-Anechoic Rooms (CFAR) have become very popular for their op- eration agility and their relatively moderate cost. The de-facto standard adopted

  13. Quality assurance procedures for environmental control and monitoring in plant growth facilities. Report of the North Central Regional 101 Committee on Growth Chamber Use

    NASA Technical Reports Server (NTRS)

    Tibbitts, T. W. (Principal Investigator)

    1986-01-01

    This report includes procedures for ensuring the quality of the environment provided for plant growth in controlled environment facilities. Biologists and engineers may use these procedures for ensuring quality control during experiments or for ensuring quality control in the design of plant growth facilities. Environmental monitoring prior to and during experiments is included in these procedures. Specific recommendations cover control, acquisition, and calibration for sensor types for the separate parameters of radiation (light), temperature, humidity, carbon dioxide, and air movement.

  14. WAKE COMPUTATIONS FOR UNDULATOR VACUUM CHAMBERS OF

    Microsoft Academic Search

    PETRA III; K. Balewski; R. Wanzenberg; E. Gjonaj; T. Weiland

    2007-01-01

    At DESY it is planned to convert the PETRA ring into a synchrotron radiation facility, called PETRA III. The wake fields of a tapered transition from the standard vacuum chamber to the small gap chamber of the insertion devices contribute significantly to the impedance budget of PETRA III. The computer codes MAFIA and PBCI have been used to determine the

  15. Leak rate measurements for large vacuum chambers

    Microsoft Academic Search

    HE Nuss; I Streuff

    1995-01-01

    For large vacuum chambers of volume between 50 and 500 m3, which are required for space simulation and thermal vacuum testing of spacecraft systems and subsystems, a specific method for the determination of the vacuum chamber leak rate is described. The main characteristics of the facility including irradiation, thermal shroud, motion and vacuum subsystem are presented. The outgassing and desorption

  16. Chamber propagation

    SciTech Connect

    Langdon, B.

    1991-01-16

    Propagation of a heavy ion beam to the target appears possible under conditions thought to be realizable by several reactor designs. Beam quality at the lens is believed to provide adequate intensity at the target -- but the beam must pass through chamber debris and its self fields along the way. This paper reviews present consensus on propagation modes and presents recent results on the effects of photoionization of the beam ions by thermal x-rays from the heated target. Ballistic propagation through very low densities is a conservative mode. The more-speculative self-pinched mode, at 1 to 10 Torr, offers reactor advantages and is being re-examined by others. 13 refs.

  17. The absorption characteristics of anechoic coating embedding mixed-cavity structure with single or double shell backing

    Microsoft Academic Search

    Chao Shang; Ying-jie Wei; Jia-zhong Zhang

    2010-01-01

    Rubber sheets embedding air cavities are wide used as anechoic coatings to reduce the energy of sound waves reflected by underwater structures, with a great military and use benefit to underwater vehicle sound stealth. According to the backing type, it can be divided into two kinds, namely rubber sheets-steel-air and rubber sheets-steel-water-steel-air, called the single and double shell backing coatings

  18. Brain Slice Chamber System

    E-print Network

    Kleinfeld, David

    Brain Slice Chamber System User's Manual BSC-BU Brain Slice Chamber System Base Unit MA1 65-0073 BSC-ZT Brain Slice Chamber System Zbicz Top MA1 65-0074 BSC-HT Brain Slice Chamber System Haas Top MA1 65-0075 BSC-PC Brain Slice Chamber System Prechamber MA1 65-0076 BSC-BUW Brain Slice Chamber Base

  19. Underwater welding test chamber

    Microsoft Academic Search

    Berghof

    1975-01-01

    An apparatus is described which is capable of testing a small hand-held welding chamber for use in underwater welding. Specifically, the apparatus includes 2 interconnected chambers, one being elevated above the other. Within the lower chamber, there is a plate on which is positioned a workpiece to be welded. The welding chamber, a tubular welding housing having a side aperture

  20. Anechoic Sphere Phantoms for Estimating 3-D Resolution of Very High Frequency Ultrasound Scanners

    PubMed Central

    Madsen, Ernest L.; Frank, Gary R.; McCormick, Matthew M.; Deaner, Meagan E.; Stiles, Timothy A.

    2013-01-01

    Two phantoms have been constructed for assessing the performance of high frequency ultrasound imagers. They also allow for periodic quality assurance tests. The phantoms contain eight blocks of tissue-mimicking material where each block contains a spatially random distribution of suitably small anechoic spheres having a small distribution of diameters. The eight mean sphere diameters are distributed from 0.10 to 1.09 mm. The two phantoms differ primarily in terms of the backscatter coefficient of the background material in which the spheres are suspended. The mean scatterer diameter for one phantom is larger than that for the other phantom resulting in a lesser increase in backscatter coefficient for the second phantom; however, the backscatter curves cross at about 35 MHz. Since spheres have no preferred orientation, all three (spatial) dimensions of resolution contribute to sphere detection on an equal basis; thus, the resolution is termed 3-D. Two high frequency scanners are compared. One employs single-element (fixed focus) transducers, and the other employs variable focus linear arrays. The nominal frequency for the single element transducers were 25 and 55 MHz and for the linear array transducers were 20, 30 and 40 MHz. The depth range for detection of spheres of each size is determined corresponding to determination of 3-D resolution as a function of depth. As expected, the single-element transducers are severely limited in useful imaging depth ranges compared with the linear arrays. Note that these phantoms could also be useful for training technicians in using higher frequency scanners. PMID:20889416

  1. Improved Bakeout Chambers Within Vacuum Chambers

    NASA Technical Reports Server (NTRS)

    Johnson, Kenneth R.; Taylor, Daniel M.; Lane, Robert W.; Cortez, Maximo G.; Anderson, Mark R.

    1995-01-01

    Improved bakeout chamber incorporates hardware features that, in conjunction with improved bakeout procedure, reduce spurious contamination and increase accuracy of contamination measurements. When operated according to revised bakeout procedure, they yield measurements of contamination on vacuum-bake test articles more accurate than available previously, and potential for post-bake recontamination of vacuum-baked articles reduced. These chambers improved versions of one described in "Bakeout Chamber Within Vacuum Chamber" (NPO-18959). By enclosing test article in enclave and keeping walls of enclave hotter than test article during bakeout, one prevents condensation of contaminants on inner walls of enclave.

  2. Optical links for microwave application

    Microsoft Academic Search

    Edward N. Toughlian; Steven T. Johns; Mark C. Schmitt

    1990-01-01

    The RADC Directorate of Communications, Communications ECCM Section, in cooperation with the RADC Photonics Laboratory, Lightwave Signal Processing Group, is in the process of replacing the existing RF cabling system of their anechoic chamber with optical links. Fiber optic links will be employed in an effort to upgrade the DCCD anechoic chamber test facility. It is expected that any electro-magnetic

  3. 'Flight effect' analysis of turbojet and turbofan nozzle models in the CEPRA 19 anechoic wind tunnel at the CEP

    NASA Astrophysics Data System (ADS)

    Fayot, C.; Gely, D.

    Measurements have been obtained at the Centre d'Essais des Propulseurs CEPRA 19 anechoic wind tunnel using turbojet and turbofan nozzle models in order to study the effect of flight velocity on jet noise. The present results are found to be in good general agreement with both theoretical results and flight test data. It is suggested that noise spectra anomalies noted at frequencies higher than 40 kHz may reflect the passage of sound waves across the mixing zone and/or the turbulent boundary layer which develops along the nozzle fuel line.

  4. Two chamber reaction furnace

    DOEpatents

    Blaugher, R.D.

    1998-05-05

    A vertical two chamber reaction furnace is described. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 C and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.

  5. A theoretical model for the evaluation of measurement uncertainty of a sound level meter calibration by comparison method in an anechoic room

    Microsoft Academic Search

    Y. T Kim; Y. B Lee; M. J Jho; S. J Suh

    2004-01-01

    A theoretical model for the evaluation of measurement uncertainty of a sound level meter (hereafter as `SLM') calibration by comparison method in an anechoic room was developed. Through this model, the uncertainties in the semi-automatic calibration and that in the full-automatic calibration were estimated for the recently developed SLM calibration system. In order to estimate the standard uncertainty against the

  6. The streamer chamber and K physics

    NASA Astrophysics Data System (ADS)

    Abashian, A.

    1980-06-01

    A view of the ZGS experimental program during the 1960's is presented, with particular emphasis upon the study of weak interactions as exhibited in neutral K meson decays and upon the study of strong interactions using the Illinois-Argonne streamer chamber facility.

  7. Evaluation of Carbon Dioxide Dissipation within a Euthanasia Chamber

    PubMed Central

    Djoufack-Momo, Shelly M; Amparan, Ashlee A; Grunden, Beverly; Boivin, Gregory P

    2014-01-01

    CO2 euthanasia is used widely for small laboratory animals, such as rodents. A common necessity in many animal research facilities is to euthanize mice in sequential batches. We assessed the effects of several variables on the time it took for CO2 to dissipate within a chamber. Using standard euthanasia time, changes in flow rate were compared between a slow 15% fill rate for 7 min, and a slow 15% followed by a rapid 50% filling for a total of 5 min. Additional variables assessed included the effects of opening the lid after the completion of chamber filling, turning the chamber over after completion of filling, and the use and removal of a cage from within the chamber. For all trials, CO2 levels in the chambers peaked between 50% and 80%. After the gas was turned off, the concentration of CO2 dropped to below 10% CO2 within 2 min, except when the lid was left on the chamber, where concentration levels remained above 10% after 20 min. CO2 dissipation was significantly faster when the chamber was turned upside down after filling. Significant interaction effects occurred among the factors of cage presence within the chamber, flow rate, and chamber position. Only leaving the lid on the chamber had any practical implication for delaying CO2 dissipation. We recommend that users allow 2 min for CO2 to clear from the chamber before subsequent euthanasia procedures, unless the chamber is manipulated to increase the dissipation rate. PMID:25199098

  8. Acoustic-RF Anechoic Chamber Construction and Evaluation Glenwood Garner III, Jonathan Wilkerson, Michael M. Skeen, Daniel F. Patrick, Ryan D. Hodges,

    E-print Network

    of sound as a means to gather information about our environment has been developed with limited scope over, acoustic materials, acoustic measurements, electromagnetic measurements, electromagnetic propagation. I recently become interested in performing ultrasonic as well as ultrasonic induced electromagnetic

  9. Controlled atmosphere exposure chamber

    Microsoft Academic Search

    R. J. Bryan; W. M. Blackmore

    1969-01-01

    A room-sized chamber was constructed capable of automatically maintaining levels of single or mixed contaminants for prolonged periods. The system can add specific contaminants to the natural smog or filter them out or do both. The chamber can house 20 dogs or subhuman primates adequately. Air flow is laminar from side to side. Several aspects of the design are discussed.

  10. The Mobile Chamber

    NASA Technical Reports Server (NTRS)

    Scharfstein, Gregory; Cox, Russell

    2012-01-01

    A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

  11. Permeability of MDT chambers to water vapor

    E-print Network

    Palestini, S

    2003-01-01

    Tests of MDT chambers performed at the GIF facility and in the H8 test-beam area have shown relative high levels of water vapor contamination in the gas-mixture at the detector output. This effects significantly the drift properties of the MDTs. This note shows that amount of water observed is compatible with approximate estimates based on the permeability of Noryl, used in the tube end-plugs, and of EPDM, used in the O-rings of the on-chamber gas distribution.

  12. Characterization of the spatial resolution of different high-frequency imaging systems using a novel anechoic-sphere phantom

    PubMed Central

    Filoux, Erwan; Mamou, Jonathan; Aristizábal, Orlando; Ketterling, Jeffrey A.

    2011-01-01

    The spatial resolution of high-frequency ultrasound (HFU, >20 MHz) imaging systems is usually determined using wires perpendicular to the beam. Recently, two tissue-mimicking phantoms (TMPs) were developed to estimate the three-dimensional (3D) resolution. Each of the TMPs consist of nine, 1 cm wide slabs of tissue-mimicking material containing randomly distributed anechoic spheres. All anechoic spheres in one slab have the same dimensions, and their diameter is increased from 0.1 mm in the first slab to 1.09 mm in the last. The scattering background for one set of slabs was fabricated using 3.5 µm glass beads, while those of the second set were 6.4 µm. The ability of a HFU system to detect these spheres against a speckle background provides a realistic estimation of its 3D spatial resolution. In the present study, these TMPs were used with HFU systems using single-element transducers, linear arrays and annular arrays. The TMPs were immersed in water and each slab was scanned using a VisualSonics™ Vevo 770 and Vevo 2100, and a custom HFU system based on a 5-element annular array. The annular array had a nominal center frequency of 40 MHz, a focal length of 12 mm, and a total aperture of 6 mm. A synthetic-focusing algorithm was used to form images with an increased depth-of-field. The penetration depth was increased by using a linear-chirp signal spanning 15 to 65 MHz over 4 µs. Results obtained with the custom system were compared to those of the Vevo systems (40 MHz probes RMV-704 and MS-550D) in terms of sphere detection, i.e., 3D spatial resolution, and contrast-to-noise ratio (CNR). Resulting B-mode images indicated that only the linear-array transducer failed to clearly resolve the 0.2 mm spheres, which showed that the 3D spatial resolution of the single-element and annular-array transducers was superior to that of the linear array. The single-element transducer could only detect these spheres over a narrow 1.5 mm depth-of-field, while the annular array was able to detect them to depths of at least 7 mm. For any size of the anechoic spheres, the annular array excited by a chirp-coded signal provided images of the highest contrast, with a maximum CNR of 1.8 at the focus, compared to 1.3 when using impulse excitation and 1.6 with the single-element transducer and linear array. This imaging configuration also provided CNRs above 1.2 over a wide depth range of 8 mm, while CNRs would quickly drop below 1 outside the focal zone of the other configurations. PMID:21622055

  13. Acoustic-Levitation Chamber

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Granett, D.; Lee, M. C.

    1984-01-01

    Uncontaminated environments for highly-pure material processing provided within completely sealed levitation chamber that suspends particles by acoustic excitation. Technique ideally suited for material processing in low gravity environment of space.

  14. Field test of electret ion chambers for environmental monitoring.

    PubMed

    Fjeld, R A; Montague, K J; Haapala, M H; Kotrappa, P

    1994-02-01

    A field test of electret ion chambers was performed to evaluate their performance in making environmental exposure measurements at nuclear facilities. The objectives of the study were to determine electret ion chamber variability and to perform comparisons with thermoluminescent dosimeter and high-pressure ion chamber measurements. Three electret ion chambers were placed at each of 40 monitoring locations in the vicinity of a commercial nuclear power station during four consecutive quarters. The electret ion chamber measurements were compared to thermoluminescent dosimeter measurements made by the Nuclear Regulatory Commission and the South Carolina Department of Health and Environmental Control. Two types of comparison were made with the high-pressure ion chamber. One used yearly average electret ion chamber measurement and instantaneous high-pressure ion chamber measurements at 15 of the monitoring locations. The other involved the simultaneous exposure of five electret ion chambers and the high-pressure ion chamber for 15 d at a single location. The mean ratios of electret ion chamber measurements to thermoluminescent dosimeter measurements was 1.06. The mean ratio of electret ion chamber measurements to instantaneous and simultaneous high-pressure ion chamber measurements were 1.06 and 1.07, respectively. Electret variability, defined here as the ratio of the standard deviation to the mean, was determined for each set of three detectors. The average variability for the 160 sets of quarterly measurements was approximately 7%. Among the 450 individual electret measurements, there were six outliers. Based on the results of this study, electret ion chambers appear to yield accurate measurements of environmental exposure provided that measures are taken to either minimize or correct for radon interferences and care is taken to prevent spurious discharges during handling. PMID:8282554

  15. Slurry-Mixing Chamber

    NASA Technical Reports Server (NTRS)

    Lewis, E. V.

    1985-01-01

    Paddles and water jets create uniform, continuous flow. Slurry-mixing chamber on hydrojet-jaw mining machine ensures uniform, continuously flowing slurry of coal particles in water. By mixing coal and water at high speed and keeping resulting slurry in constant motion, chamber prevents slurry from becoming dry semisolid that blocks flow. Also prevents coal particles from settling and caking in bends, corners, and other locations where flow changes in direction or speed.

  16. Sleeve reaction chamber system

    DOEpatents

    Northrup, M. Allen (Berkeley, CA); Beeman, Barton V. (San Mateo, CA); Benett, William J. (Livermore, CA); Hadley, Dean R. (Manteca, CA); Landre, Phoebe (Livermore, CA); Lehew, Stacy L. (Livermore, CA); Krulevitch, Peter A. (Pleasanton, CA)

    2009-08-25

    A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

  17. Filament wound rocket motor chambers

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The design, analysis, fabrication and testing of a Kevlar-49/HBRF-55A filament wound chamber is reported. The chamber was fabricated and successfully tested to 80% of the design burst pressure. Results of the data reduction and analysis from the hydrotest indicate that the chamber design and fabrication techniques used for the chamber were adequate and the chamber should perform adequately in a static test.

  18. Automated soil gas monitoring chamber

    DOEpatents

    Edwards, Nelson T.; Riggs, Jeffery S.

    2003-07-29

    A chamber for trapping soil gases as they evolve from the soil without disturbance to the soil and to the natural microclimate within the chamber has been invented. The chamber opens between measurements and therefore does not alter the metabolic processes that influence soil gas efflux rates. A multiple chamber system provides for repetitive multi-point sampling, undisturbed metabolic soil processes between sampling, and an essentially airtight sampling chamber operating at ambient pressure.

  19. Optical testing cryogenic thermal vacuum facility

    Microsoft Academic Search

    Patrick W. Dohogne; Warren A. Carpenter

    1990-01-01

    The construction of a turnkey cryogenic vacuum test facility was recently completed. The facility will be used to measure and record the surface profile of large diameter and 540 kg optics under simulated space conditions. The vacuum test chamber is a vertical stainless steel cylinder with a 3.5 diameter and a 7 m tangent length. The chamber was designed to

  20. Solar thermal plasma chamber

    Microsoft Academic Search

    Joseph Bonometti; Donald R. Buchele; Charles H. Castle; Don A. Gregory

    2001-01-01

    A unique solar thermal chamber has been designed and fabricated to produce the maximum concentration of solar energy and highest temperature possible. Its primary purpose was for solar plasma propulsion experiments and related material specimen testing above 3000 Kelvin. The design not only maximized solar concentration, but also, minimized infrared heat loss. This paper provides the underlining theory and operation

  1. Engine combustion chamber structure

    Microsoft Academic Search

    Tanaka

    1988-01-01

    This patent describes a combustion chamber structure comprising an upper wall surface which is shaped like a pent-roof and into which an intake passage opens, a piston having on a head portion thereof a bulged portion conforming to the upper wall surface in shape, a first bowl portion which is formed substantially at the center of the bulged portion and

  2. Liquid Wall Chambers

    SciTech Connect

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  3. Bubble Chamber Site

    NSDL National Science Digital Library

    This substantial site features a large number of photos of bubble chamber (BC) tracks, many with a discussion of the physics. There is a description of how the BC works and also useful tutorial on reading BC pictures. The high quality of the images and the explanations of the events that are shown make this site especially valuable.

  4. 72. VISITOR'S CENTER, MODEL OF BOILER CHAMBER, AUXILIARY CHAMBER, REACTOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. VISITOR'S CENTER, MODEL OF BOILER CHAMBER, AUXILIARY CHAMBER, REACTOR AND CANAL (LOCATION T) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  5. Terminal configured vehicle program: Test facilities guide

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The terminal configured vehicle (TCV) program was established to conduct research and to develop and evaluate aircraft and flight management system technology concepts that will benefit conventional take off and landing operations in the terminal area. Emphasis is placed on the development of operating methods for the highly automated environment anticipated in the future. The program involves analyses, simulation, and flight experiments. Flight experiments are conducted using a modified Boeing 737 airplane equipped with highly flexible display and control equipment and an aft flight deck for research purposes. The experimental systems of the Boeing 737 are described including the flight control computer systems, the navigation/guidance system, the control and command panel, and the electronic display system. The ground based facilities used in the program are described including the visual motion simulator, the fixed base simulator, the verification and validation laboratory, and the radio frequency anechoic facility.

  6. Three chamber negative ion source

    DOEpatents

    Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA); Hiskes, John R. (Livermore, CA)

    1985-01-01

    A negative ion vessel is divided into an excitation chamber, a negative ionization chamber and an extraction chamber by two magnetic filters. Input means introduces neutral molecules into a first chamber where a first electron discharge means vibrationally excites the molecules which migrate to a second chamber. In the second chamber a second electron discharge means ionizes the molecules, producing negative ions which are extracted into or by a third chamber. A first magnetic filter prevents high energy electrons from entering the negative ionization chamber from the excitation chamber. A second magnetic filter prevents high energy electrons from entering the extraction chamber from the negative ionizing chamber. An extraction grid at the end of the negative ion vessel attracts negative ions into the third chamber and accelerates them. Another grid, located adjacent to the extraction grid, carries a small positive voltage in order to inhibit positive ions from migrating into the extraction chamber and contour the plasma potential. Additional electrons can be suppressed from the output flux using ExB forces provided by magnetic field means and the extractor grid electric potential.

  7. Multiwire proportional chamber development

    NASA Technical Reports Server (NTRS)

    Doolittle, R. F.; Pollvogt, U.; Eskovitz, A. J.

    1973-01-01

    The development of large area multiwire proportional chambers, to be used as high resolution spatial detectors in cosmic ray experiments is described. A readout system was developed which uses a directly coupled, lumped element delay-line whose characteristics are independent of the MWPC design. A complete analysis of the delay-line and the readout electronic system shows that a spatial resolution of about 0.1 mm can be reached with the MWPC operating in the strictly proportional region. This was confirmed by measurements with a small MWPC and Fe-55 X-rays. A simplified analysis was carried out to estimate the theoretical limit of spatial resolution due to delta-rays, spread of the discharge along the anode wire, and inclined trajectories. To calculate the gas gain of MWPC's of different geometrical configurations a method was developed which is based on the knowledge of the first Townsend coefficient of the chamber gas.

  8. Recommendations for chamber quantification

    Microsoft Academic Search

    Roberto M. Lang; Michelle Bierig; Richard B. Devereux; Frank A. Flachskampf; Elyse Foster; Patricia A. Pellikka; Michael H. Picard; Mary J. Roman; James Seward; Jack Shanewise; Scott Solomon; Kirk T. Spencer; John Sutton; William Stewart

    2006-01-01

    Abstract Quantification of cardiac chamber size, ventricular mass and function ranks among,the most,clinically important,and most,frequently,requested,tasks of echocardiography. Over the last decades, echocardiographic methods and techniques haveimprovedandexpandeddramatically,duetotheintroductionofhigherfrequency transducers, harmonic imaging, fully digital machines, left-sided contrast agents, and other technological advancements. Furthermore, echocardiography due to its porta- bility and versatility is now used in emergency rooms, operating rooms, and intensive care units.

  9. Engine combustion chamber structure

    SciTech Connect

    Tanaka, H.

    1988-09-13

    This patent describes a combustion chamber structure comprising an upper wall surface which is shaped like a pent-roof and into which an intake passage opens, a piston having on a head portion thereof a bulged portion conforming to the upper wall surface in shape, a first bowl portion which is formed substantially at the center of the bulged portion and which is substantially semispherical in shape, a pair of second bowl portions which respectively extend on opposite sides of the first bowl portion to the corresponding ends of the bulged portion of the piston along the edge of the bulged portion and are in communication with the first bowl portion, a swirl generating means which is adapted to generate a swirl of intake air in the combustion chamber when the engine load is light, and a spark plug disposed to substantially face the center of the first bowl portion from the upper wall surface; the swirl generating means being adapted to generate the swirl of intake air in a tangential direction in the combustion chamber; and the diameter of the first bowl portion being larger than the width of the second bowl portion.

  10. MAIN CHAMBER NEUTRAL PRESSURE IN

    E-print Network

    Pitcher, C. S.

    MAIN CHAMBER NEUTRAL PRESSURE IN ALCATOR C-MOD AND JET C S Pitcher, S K Erents*, W Fundamenski*, B on Controlled Fusion and Plasma Physics 18 ­ 22 June 1999, Madeira, Portugal MAIN CHAMBER NEUTRAL PRESSURE Science Centre, Abingdon, Oxon OX14 3DB,UK #12;(1) Introduction · main chamber gas can have a number

  11. LOX cooled thrust chamber technology developments

    NASA Technical Reports Server (NTRS)

    Spencer, R. G.; Rousar, D. C.; Price, H. G.

    1978-01-01

    An experimental LOX heat-transfer study and a LOX-cooled thrust-chamber demonstration program are summarized. Heat transfer to supercritical oxygen was investigated at 17 to 34.5 MPa (2460 to 5000 psia), and heat fluxes up to 90 MW/sq m (55 Btu/sq in.-sec). Experimental data obtained previously were correlated along with these recent data, and a design equation was derived which correlates 95% of the data within + or - 30%. Liquid-oxygen-cooled thrust chambers have been designed using this correlation and are currently being fabricated. A test program is planned for evaluating the LOX-cooled design concept using NASA test facilities. The purpose of these tests is to verify the LOX cooling correlation in a high-pressure liquid rocket engine and to determine the effects of a LOX coolant leak.

  12. Organic compound destruction and removal efficiency (DRE) for plasma incinerator off-gases using an electrically heated secondary combustion chamber 1 Work performed at MSE Technology Applications, Inc., Plasma Test Facility, 200 Technology Way, Butte, MT 59702, USA. 1

    Microsoft Academic Search

    C. G. Whitworth; S. Babko-Malyi; D. M. Battleson; S. J. Olstad

    1998-01-01

    The United States Department of Energy (DOE) sponsored a series pilot-scale plasma incineration tests of simulated mixed wastes at the MSE Technology Applications, Inc. technology development test facility in Butte, MT. One of the objectives of the test series was to assess the ability of an electrically heated afterburner to destroy organic compounds that may be present in the off-gases

  13. Multi-anode ionization chamber

    DOEpatents

    Bolotnikov, Aleksey E. (South Setauket, NY); Smith, Graham (Port Jefferson, NY); Mahler, George J. (Rocky Point, NY); Vanier, Peter E. (Setauket, NY)

    2010-12-28

    The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.

  14. Review of wire chamber aging

    SciTech Connect

    Va'Vra, J.

    1986-02-01

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs.

  15. Initial Back-to-Back Fission Chamber Testing in ATRC

    SciTech Connect

    Benjamin Chase; Troy Unruh; Joy Rempe

    2014-06-01

    Development and testing of in-pile, real-time neutron sensors for use in Materials Test Reactor experiments is an ongoing project at Idaho National Laboratory. The Advanced Test Reactor National Scientific User Facility has sponsored a series of projects to evaluate neutron detector options in the Advanced Test Reactor Critical Facility (ATRC). Special hardware was designed and fabricated to enable testing of the detectors in the ATRC. Initial testing of Self-Powered Neutron Detectors and miniature fission chambers produced promising results. Follow-on testing required more experiment hardware to be developed. The follow-on testing used a Back-to-Back fission chamber with the intent to provide calibration data, and a means of measuring spectral indices. As indicated within this document, this is the first time in decades that BTB fission chambers have been used in INL facilities. Results from these fission chamber measurements provide a baseline reference for future measurements with Back-to-Back fission chambers.

  16. Automated protein crystal growth facility

    NASA Technical Reports Server (NTRS)

    Donald, Stacey

    1994-01-01

    A customer for the protein crystal growth facility fills the specially designed chamber with the correct solutions, fills the syringes with their quenching solutions, and submits the data needed for the proper growth of their crystal. To make sure that the chambers and syringes are filled correctly, a NASA representative may assist the customer. The data needed is the approximate growth time, the growth temperature, and the desired crystal size, but this data can be changed anytime from the ground, if needed. The chambers are gathered and placed into numbered slots in special drawers. Then, data is entered into a computer for each of the chambers. Technicians map out when each chamber's growth should be activated so that all of the chambers have enough time to grow. All of this data is up-linked to the space station when the previous growth session is over. Anti-vibrational containers need to be constructed for the high forces encountered during the lift off and the landing of the space shuttle, and though our team has not designed these containers, we do not feel that there is any reason why a suitable one could not be made. When the shuttle reaches the space station, an astronaut removes a drawer of quenched chambers from the growth facility and inserts a drawer of new chambers. All twelve of the drawers can be replaced in this fashion. The optical disks can also be removed this way. The old drawers are stored for the trip back to earth. Once inside the growth facility, a chamber is removed by the robot and placed in one of 144 active sites at a time previously picked by a technician. Growth begins when the chamber is inserted into an active site. Then, the sensing system starts to determine the size of the protein crystal. All during the crystal's growth, the customer can view the crystal and read all of the crystal's data, such as growth rate and crystal size. When the sensing system determines that the crystal has reached the predetermined size, the robot is told to pick up a syringe filled with the correct quenchant solution and inject it into the chamber to stop the crystal growth. The chamber is then removed from the active site and placed into its original storage slot. Another chamber is then placed into the active site and the process is repeated in all of the active sites until all of the chambers have complted their growth. After ninety days (the scheduled time between shuttle visits), the crystal growth is completed, and the old drawers are replaced with new ones. Once the customer extracts the crystals, the chambers are retrieved for future customers.

  17. Overview of the ICF 1000 MJ experiment chamber design

    SciTech Connect

    Slaughter, D.

    1988-09-23

    A conceptual design of an experiment chamber for a high gain ICF facility (1000 MJ) is being developed. Performance goals have been established. Several design approaches are being evaluated through computer simulation, engineering analysis, and experimental testing of candidate first wall components. 10 refs., 3 figs.

  18. Computation of Neutral Gas Flow From a Hall Thruster Into a Vacuum Chamber

    E-print Network

    Walker, Mitchell

    -density background neutral gas due to physical pumping limitations and the leak rate of the facility. As gasComputation of Neutral Gas Flow From a Hall Thruster Into a Vacuum Chamber Iain D. Boyd, Chunpei to model a cold flow of xenon gas expanding from a Hall thruster into a vacuum chamber. The simulations

  19. BOREAS TGB-1/TGB-3 CH4 Chamber Flux Data over the NSA Fen

    NASA Technical Reports Server (NTRS)

    Bubier, Jill L.; Moore, Tim R.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

    2000-01-01

    The BOREAS TGB-3 team collected methane (CH4) chamber flux measurements at the NSA fen site during May-September 1994 and June-October 1996. Gas samples were extracted approximately every 7 days from chambers and analyzed at the NSA lab facility. The data are provided in tabular ASCII files.

  20. AUTOMATED CORRECTION ON X-RAYS CALIBRATION USING TRANSMISSION CHAMBER AND LAB VIEW ™ ™ ™

    Microsoft Academic Search

    Flávio Betti; Maria da Penha; Albuquerque Potiens

    Uncertainties during prolonged exposure times on X-rays calibration procedures at the Instruments Cali bration facilities at IPEN may suffer from efficiency (and therefore intensity) variations on the industrial X -Ray generator used. Using a transmission chamber as an online reference chamber during the whole irradiati on process is proposed in order to compensate for such error source. Also temperature (and

  1. A comparison of the acoustic and aerodynamic measurements of a model rotor tested in two anechoic wind tunnels

    NASA Technical Reports Server (NTRS)

    Boxwell, D. A.; Schmitz, F. H.; Splettstoesser, W. R.; Schultz, K. J.; Lewy, S.; Caplot, M.

    1986-01-01

    Two aeroacoustic facilities--the CEPRA 19 in France and the DNW in the Netherlands--are compared. The two facilities have unique acoustic characteristics that make them appropriate for acoustic testing of model-scale helicopter rotors. An identical pressure-instrumented model-scale rotor was tested in each facility and acoustic test results are compared with full-scale-rotor test results. Blade surface pressures measured in both tunnels were used to correlated nominal rotor operating conditions in each tunnel, and also used to assess the steadiness of the rotor in each tunnel's flow. In-the-flow rotor acoustic signatures at moderate forward speeds (35-50 m/sec) are presented for each facility and discussed in relation to the differences in tunnel geometries and aeroacoustic characteristics. Both reports are presented in appendices to this paper. ;.);

  2. Neutron Detection via Bubble Chambers

    SciTech Connect

    Jordan, David V.; Ely, James H.; Peurrung, Anthony J.; Bond, Leonard J.; Collar, J. I.; Flake, Matthew; Knopf, Michael A.; Pitts, W. K.; Shaver, Mark W.; Sonnenschein, Andrew; Smart, John E.; Todd, Lindsay C.

    2005-10-06

    The results of a Pacific Northwest National Laboratory (PNNL) exploratory research project investigating the feasibility of fast neutron detection using a suitably prepared and operated, pressure-cycled bubble chamber are described. The research was conducted along two parallel paths. Experiments with a slow pressure-release Halon chamber at the Enrico Fermi Institute at the University of Chicago showed clear bubble nucleation sensitivity to an AmBe neutron source and insensitivity to the 662 keV gammas from a 137Cs source. Bubble formation was documented via high-speed (1000 frames/sec) photography, and the acoustic signature of bubble formation was detected using a piezo-electric transducer element mounted on the base of the chamber. The chamber’s neutron sensitivity as a function of working fluid temperature was mapped out. The second research path consisted of the design, fabrication, and testing of a fast pressure-release Freon-134a chamber at PNNL. The project concluded with successful demonstrations of the PNNL chamber’s AmBe neutron source sensitivity and 137Cs gamma insensitivity. The source response tests of the PNNL chamber were documented with high-speed photography.

  3. Diogene pictorial drift chamber

    NASA Astrophysics Data System (ADS)

    Gosset, J.

    1984-02-01

    A pictorial drift chamber, called DIOGENE, has been installed at Saturne in order to study central collisions of high energy heavy ions. It has been adapted from the JADE internal detector, with two major differences to be taken into account. First, the center-of-mass of these collisions is not identical to the laboratory reference frame. Second, the energy loss and the momentum ranges of the particles to be detected are different from the ones in JADE. It was also tried to keep the cost as small as possible, hence the choice of minimum size and minimum number of sensitive wires. Moreover the wire planes are shifted from the beam axis: this trick helps very much to quickly reject the bad tracks caused by the ambiguity of measuring drift distances (positive or negative) through times (always positive).

  4. Chambers's Book of Days

    NSDL National Science Digital Library

    Subtitled A Miscellany of Popular Antiquities in connection with the Calendar, Chambers's Book of Days is essentially a collection of "On this Day" trivia, short pieces, and other interesting tidbits, including history, literature, biography, and "oddities of human life and character." Digitized by the University of Wisconsin-Madison Libraries, this electronic reprint may be browsed in page order or via a calendar navigator. The site offers a fun look into pop-history/ tabloid news of the late nineteenth century. For instance, I discovered that on the day of my birth in 1626 "a cod-fish was brought to Cambridge market, which upon being opened, was found to contain a book in its maw or stomach." An auspicious date to be born indeed.

  5. Diogene pictorial drift chamber

    SciTech Connect

    Gosset, J.

    1984-01-01

    A pictorial drift chamber, called DIOGENE, has been installed at Saturne in order to study central collisions of high energy heavy ions. It has been adapted from the JADE internal detector, with two major differences to be taken into account. First, the center-of-mass of these collisions is not identical to the laboratory reference frame. Second, the energy loss and the momentum ranges of the particles to be detected are different from the ones in JADE. It was also tried to keep the cost as small as possible, hence the choice of minimum size and minimum number of sensitive wires. Moreover the wire planes are shifted from the beam axis: this trick helps very much to quickly reject the bad tracks caused by the ambiguity of measuring drift distances (positive or negative) through times (always positive).

  6. Iran Chamber Society

    NSDL National Science Digital Library

    In 2001, the Iran Chamber Society was created in order to provide a non-partisan, non-commercial, comprehensive source of information on Iran. The website's "About Us" section states that their aim is to "create a global awareness about Iranian society and eradicate the misunderstandings and misconceptions about Iranian society, and to play an educational role as well." Visitors will find the website divided up into "Art and Culture", "History", "Society" and "Iran's Guide". The "Exhibitions and Conferences" link on the right side of the homepage leads visitors to a number of exhibitions, including the fascinating "Artistic Murals of Tehran's Metro Stations", which offers a dozen pictures of the beautifully handcrafted murals made of pottery, metal, cement and other materials. The "History" section offers pictures and documents, including some disturbing graphic photos from the Iran-Iraq War in 1980-1988 that appear at the end of the Historic Periods and Events section.

  7. HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF PLENUM WITH ATTACHED DRAFT REGULATOR. - Hot Springs National Park, Bathhouse Row, Superior Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  8. Small rocket flowfield diagnostic chambers

    NASA Astrophysics Data System (ADS)

    Morren, Sybil; Reed, Brian

    1993-11-01

    Instrumented and optically-accessible rocket chambers are being developed to be used for diagnostics of small rocket (less than 440 N thrust level) flowfields. These chambers are being tested to gather local fluid dynamic and thermodynamic flowfield data over a range of test conditions. This flowfield database is being used to better understand mixing and heat transfer phenomena in small rockets, influence the numerical modeling of small rocket flowfields, and characterize small rocket components. The diagnostic chamber designs include: a chamber design for gathering wall temperature profiles to be used as boundary conditions in a finite element heat flux model; a chamber design for gathering inner wall temperature and static pressure profiles; and optically-accessible chamber designs, to be used with a suite of laser-based diagnostics for gathering local species concentration, temperature, density, and velocity profiles. These chambers were run with gaseous hydrogen/gaseous oxygen (GH2/GO2) propellants, while subsequent versions will be run on liquid oxygen/hydrocarbon (LOX/HC) propellants. The purpose, design, and initial test results of these small rocket flowfield diagnostic chambers are summarized.

  9. Ion chamber based neutron detectors

    DOEpatents

    Derzon, Mark S; Galambos, Paul C; Renzi, Ronald F

    2014-12-16

    A neutron detector with monolithically integrated readout circuitry, including: a bonded semiconductor die; an ion chamber formed in the bonded semiconductor die; a first electrode and a second electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; and the readout circuitry which is electrically coupled to the first and second electrodes. The bonded semiconductor die includes an etched semiconductor substrate bonded to an active semiconductor substrate. The readout circuitry is formed in a portion of the active semiconductor substrate. The ion chamber has a substantially planar first surface on which the first electrode is formed and a substantially planar second surface, parallel to the first surface, on which the second electrode is formed. The distance between the first electrode and the second electrode may be equal to or less than the 50% attenuation length for neutrons in the neutron absorbing material filling the ion chamber.

  10. Anterior chamber depth during hemodialysis

    PubMed Central

    Gracitelli, Carolina Pelegrini Barbosa; Stefanini, Francisco Rosa; Penha, Fernando; Góes, Miguel Ângelo; Draibe, Sérgio Antonio; Canziani, Maria Eugênia; Junior, Augusto Paranhos

    2013-01-01

    Background Exacerbation of chronic glaucoma or acute glaucoma is occasionally observed in patients undergoing hemodialysis (HD) because of anterior chamber depth changes during this therapy. Purpose To evaluate anterior chamber depth and axial length in patients during HD sessions. Methods A total of 67 eyes of 35 patients were prospectively enrolled. Axial length and anterior chamber depth were measured using ultrasonic biometry, and these measures were evaluated at three different times during HD sessions. Body weight and blood pressure pre- and post-HD were also measured. Results There was no difference in the axial length between the three measurements (P = 0.241). We observed a significantly decreased anterior chamber depth (P = 0.002) during HD sessions. Conclusion Our results support the idea that there is a change in anterior chamber depth in HD sessions. PMID:23976841

  11. Proton beam monitor chamber calibration.

    PubMed

    Gomà, C; Lorentini, S; Meer, D; Safai, S

    2014-09-01

    The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences-of the order of 3%-were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth-i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers-rather than cylindrical chambers-for the reference dosimetry of pseudo-monoenergetic proton beams. PMID:25109620

  12. Proton beam monitor chamber calibration

    NASA Astrophysics Data System (ADS)

    Gomà, C.; Lorentini, S.; Meer, D.; Safai, S.

    2014-09-01

    The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences—of the order of 3%—were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth—i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers—rather than cylindrical chambers—for the reference dosimetry of pseudo-monoenergetic proton beams.

  13. Combustion chamber for internal combustion engine

    Microsoft Academic Search

    Isida

    1988-01-01

    This patent describes a combustion chamber for an internal combustion engine, comprising: a main combustion chamber hollowed out of the top of a piston; a subsidiary combustion chamber hollowed out of the piston top, the subsidiary combustion chamber communicating with and disposed in side by side relationship to the main combustion chamber; a fuel injection nozzle located generally between the

  14. Starting a High School Chamber Music Group.

    ERIC Educational Resources Information Center

    Rutkowski, Joseph

    2000-01-01

    Presents ideas on how to begin a chamber music ensemble. Discusses how to find time to accomplish chamber music playing in and around the school day. Presents short descriptions of chamber music that can be used with ensembles. Includes chamber music resources and additional chamber works. (CMK)

  15. Multiple piston expansion chamber engine

    SciTech Connect

    Jackson, F.W.

    1986-04-08

    This patent describes a multiple piston expansion chamber in an internal combustion engine wherein combustion, expansion and exhaust functions are performed in a cylinder. This cylinder consists of an auxiliary piston reciprocating in the cylinder, a sleeve valve reciprocating within the auxiliary piston, a working piston reciprocating within the sleeve valve. Leading the auxiliary piston is an auxiliary chamber above the auxiliary piston and a combustion chamber above the working piston. The sleeve valve controls communication of the auxiliary chamber with the combustion chamber to prevent communication of combusted products from the chamber above the working piston to the chamber above the auxiliary piston from when the working piston is at about TDC until a subsequent expansion stroke of the working piston is underway to a point about midway to BDC. When the auxiliary piston is at about TDC at this same instant when the working piston is at the point and the communication then is commenced. In order to permit communication only during the expansion stroke from continuing past the point and a following exhaust stroke of the working piston so as to utilize energy of expansion from the auxiliary piston as it expands until the working piston has passed through BDC and returns to about TDC during the exhaust stroke of the working piston. The controlling means comprises a circular sealing surface on an upward viewing surface of the sleeve valve adjacent to the working piston to prevent communication of the respective chambers. Also provided in the chambers is a dwell of the sleeve valve at its TDC between when the respective pistons each reach their TDC.

  16. Ultraviolet laser calibration of drift chambers

    E-print Network

    Elliott, Grant (Grant Andrew)

    2006-01-01

    We demonstrate the use of a focused ultraviolet laser as a track calibration source in drift chambers, and specifically in a small time projection chamber (TPC). Drift chambers such as TPCs reconstruct the trajectories of ...

  17. Ames Hybrid Combustion Facility

    NASA Technical Reports Server (NTRS)

    Zilliac, Greg; Karabeyoglu, Mustafa A.; Cantwell, Brian; Hunt, Rusty; DeZilwa, Shane; Shoffstall, Mike; Soderman, Paul T.; Bencze, Daniel P. (Technical Monitor)

    2003-01-01

    The report summarizes the design, fabrication, safety features, environmental impact, and operation of the Ames Hybrid-Fuel Combustion Facility (HCF). The facility is used in conducting research into the scalability and combustion processes of advanced paraffin-based hybrid fuels for the purpose of assessing their applicability to practical rocket systems. The facility was designed to deliver gaseous oxygen at rates between 0.5 and 16.0 kg/sec to a combustion chamber operating at pressures ranging from 300 to 900. The required run times were of the order of 10 to 20 sec. The facility proved to be robust and reliable and has been used to generate a database of regression-rate measurements of paraffin at oxygen mass flux levels comparable to those of moderate-sized hybrid rocket motors.

  18. 21 CFR 866.2120 - Anaerobic chamber.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a...

  19. 21 CFR 866.2120 - Anaerobic chamber.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a...

  20. 21 CFR 866.2120 - Anaerobic chamber.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a...

  1. 21 CFR 866.2120 - Anaerobic chamber.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a...

  2. 21 CFR 866.2120 - Anaerobic chamber.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a...

  3. Extra Terrestrial Environmental Chamber Design

    NASA Technical Reports Server (NTRS)

    Hughes, David W.

    2008-01-01

    A vacuum chamber designed to simulate the dusty environment on the Moon or Mars has been built for Goddard Space Flight Center. The path from concept to delivery is reviewed, with lessons learned and pitfalls highlighted along the way.

  4. Numerical grid generation and flow simulation in SSME thrust chamber

    SciTech Connect

    Gross, K.W.; Daley, P.L.; Przekwas, A.J.

    1987-01-01

    The development of liquid and solid rocket engines for future space projects demands a detailed optimization process for highly efficient performance and cost reasons. Also, testing of full size engines may not be feasible when the large size requires test facilities which are cost prohibitive or if vacuum operation cannot be acquired. For such situations only scaling from small test scale measurements or accurate analytical predictions will provide the performance prior to actually flying the mission. A rigorous approach for simulating the combustion processes in liquid rocket engines by employing a direct solution of Navier-Stokes equations within the entire volume of the thrust chambers is presented. This method is illustrated in the solution of reactive flow in the Space Shuttle Main Engine (SSME) thrust chamber. The objective is to review recent improvements in the mathematical model and to present the grid generation methodology suitable for rocket thrust chamber geometries.

  5. Spectra, composition, and interactions of nuclei with magnet interaction chambers

    NASA Technical Reports Server (NTRS)

    Parneil, T. A.; Derrickson, J. H.; Fountain, W. F.; Roberts, F. E.; Tabuki, T.; Watts, J. W.; Burnett, T. H.; Cherry, M. C.; Dake, S.; Fuki, M.

    1990-01-01

    Emulsion chambers will be flown in the Astromag Facility to measure the cosmic ray composition and spectra to 10 exp 15 eV total energy and to definitively study the characteristics of nucleus-nucleus interactions above 10 exp 12 eV/n. Two configurations of emulsion chambers will be flown in the SCIN/MAGIC experiment. One chamber has an emulsion target and a calorimeter similar to those recently flown on balloons for composition and spectra measurements. The other has an identical calorimeter and a low-density target section optimized for performing rigidity measurements on charged particles produced in interactions. The transverse momenta of charged and neutral mesons, direct hadronic pairs from resonance decays and interference effects, and possible charge clustering in high-density states of matter will be studied.

  6. Light diffusing fiber optic chamber

    DOEpatents

    Maitland, Duncan J. (Lafayette, CA)

    2002-01-01

    A light diffusion system for transmitting light to a target area. The light is transmitted in a direction from a proximal end to a distal end by an optical fiber. A diffusing chamber is operatively connected to the optical fiber for transmitting the light from the proximal end to the distal end and transmitting said light to said target area. A plug is operatively connected to the diffusing chamber for increasing the light that is transmitted to the target area.

  7. Multiple piston expansion chamber engine

    SciTech Connect

    Jackson, F.W.

    1986-02-18

    This patent describes an internal combustion engine. This engine consists of a cylinder with an auxiliary piston reciprocating in the cylinder; a working piston reciprocating within the auxiliary piston; an auxiliary chamber above the auxiliary piston; a combustion chamber above the working piston and providing a dwell for the auxiliary piston at TDC starting from when the working piston is between 40 degrees before to about TDC and on passing TDC entering an expansion stroke. The auxiliary piston remains at TDC until the working piston expansion stroke is underway and at a point where the working piston is between 20 and 160 degrees past TDC during the expansion stroke at which point the auxiliary piston leaves TDC and moves toward BDC. A controller communicating with the combustion chamber and the auxiliary chamber to prevent communication of combusted products from the combustion chamber above the working piston to the chamber above the auxiliary piston while the auxiliary piston is at TDC. The piston at TDC permits communication only during the working piston expansion stroke continuing past the point between 20 and 160 degrees past TDC, and a following exhaust stroke of the working piston so as to utilize energy of expansion from the auxiliary piston as it expands until the working piston has passed through BDC and returns to about TDC during the exhaust stroke of the working piston.

  8. Multiple piston expansion chamber engine

    SciTech Connect

    Jackson, F.W.

    1987-12-29

    An internal combustion engine is described wherein combustion, expansion and exhaust functions are performed in a cylinder comprised of an auxiliary piston reciprocating in the cylinder, a sleeve valve reciprocating within the auxiliary piston, a working piston reciprocating within the sleeve valve and leading the auxiliary piston, an auxiliary chamber above the auxiliary piston and a combustion chamber above the working piston. The sleeve valve controlling communication of the auxiliary chamber with the combustion chamber to prevent communication of combusted products from the chamber above the working piston to the chamber above the auxiliary piston from when the working piston is at about TDC until a subsequent expansion stroke of the working piston is underway and at a point between 30 and 160 degrees past TDC and with the auxiliary piston being at about TDC at this same instant when the working piston is at the point and the communication then is commenced. To permit communication only during the expansion stroke continuing past the point and a following exhaust stroke of the working piston so as to utilize energy of expansion from the auxiliary piston as it expands until the working piston has passed through BDC and returns to about TDC during the exhaust stroke of the working piston.

  9. Planning and preliminary design of a contained firing chamber to resist blast effects of 60kg of energetic chemical explosive

    Microsoft Academic Search

    J. W. Pastrnak; C. F. Baker; L. F. Simmons

    1993-01-01

    The Lawrence Livermore National Laboratory (LLNL) Nuclear Weapons Design Program operates explosive testing facilities at its Site 300 open air explosive test facility. LLNL is developing a blast containment facility to reduce emissions of hazardous materials and reduce the amount of contaminated waste generated from explosive testing of chemical explosives. The firing chamber is designed to contain the blast over

  10. Evaluation of Impinging Stream Vortex Chamber Concepts for Liquid Rocket Engine Applications

    NASA Technical Reports Server (NTRS)

    Trinh, Huu P.; Bullard, Brad; Kopicz, Charles; Michaels, Scott

    2002-01-01

    To pursue technology developments for future launch vehicles, NASA/Marshall Space Flight Center (MSFC) is examining vortex chamber concepts for liquid rocket engine applications. Past studies indicated that the vortex chamber schemes potentially have a number of advantages over conventional chamber methods. Due to the nature of the vortex flow, relatively cooler propellant streams tend to flow along the chamber wall. Hence, the thruster chamber can be operated without the need of any cooling techniques. This vortex flow also creates strong turbulence, which promotes the propellant mixing process. Consequently, the subject chamber concepts not only offer system simplicity, but also enhance the combustion performance. Test results have shown that chamber performance is markedly high even at a low chamber length-to-diameter ratio (LD). This incentive can be translated to a convenience in the thrust chamber packaging. Variations of the vortex chamber concepts have been introduced in the past few decades. These investigations include an ongoing work at Orbital Technologies Corporation (ORBITEC). By injecting the oxidizer tangentially at the chamber convergence and fuel axially at the chamber head end, Knuth et al. were able to keep the wall relatively cold. A recent investigation of the low L/D vortex chamber concept for gel propellants was conducted by Michaels. He used both triplet (two oxidizer orifices and one fuel orifice) and unlike impinging schemes to inject propellants tangentially along the chamber wall. Michaels called the subject injection scheme an Impinging Stream Vortex Chamber (ISVC). His preliminary tests showed that high performance, with an Isp efficiency of 9295, can be obtained. MSFC and the U. S. Army are jointly investigating an application of the ISVC concept for the cryogenic oxygen/hydrocarbon propellant system. This vortex chamber concept is currently tested with gel propellants at AMCOM at Redstone Arsenal, Alabama. A version of this concept for the liquid oxygen (LOX) hydrocarbon fuel (RP-1) system has been derived from the one for the gel propellant. An unlike impinging injector was employed to deliver the propellants to the chamber. MSFC is also conducting an alternative injection scheme, called the chasing injector, associated with this vortex chamber concept. In this injection technique, both propellant jets and their impingement point are in the same chamber cross-sectional plane. Long duration tests (approximately up to 15 seconds) will be conducted on the ISVC to study the thermal effects. This paper will report the progress of the subject efforts at NASA Marshall Space Flight Center. Thrust chamber performance and thermal wall compatibility will be evaluated. The chamber pressures, wall temperatures, and thrust will be measured as appropriate. The test data will be used to validate CFD models, which, in turn, will be used to design the optimum vortex chambers. Measurements in the previous tests showed that the chamber pressures vary significantly with radius. This is due to the existence of the vortices in the chamber flow field. Hence, the combustion efficiency may not be easily determined from chamber pressure. For this project, measured thrust data will be collected. The performance comparison will be in terms of specific impulse efficiencies. In addition to the thrust measurements, several pressure and temperature readings at various locations on the chamber head faceplate and the chamber wall will be made. The first injector and chamber were designed and fabricated based on the available data and experience gained during gel propellant system tests by the U.S. Army. The alternate injector for the ISVC was also fabricated. Hot-fire tests of the vortex chamber are about to start and are expected to complete in February of 2003 at the TS115 facility of MSFC.

  11. Characterization and testing of a new environmental chamber

    NASA Astrophysics Data System (ADS)

    Leskinen, A.; Yli-Pirilä, P.; Kuuspalo, K.; Sippula, O.; Jalava, P.; Hirvonen, M.-R.; Jokiniemi, J.; Virtanen, A.; Komppula, M.; Lehtinen, K. E. J.

    2015-06-01

    A 29 m3 Teflon chamber, designed for studies on the aging of combustion aerosols, at the University of Eastern Finland is described and characterized. The chamber is part of a research facility, called Ilmari, where small-scale combustion devices, a dynamometer for vehicle exhaust studies, dilution systems, the chamber, and cell and animal exposure devices are located side by side under the same roof. The small surface-to-volume ratio of the chamber enables reasonably long experiment times, with particle wall loss rate constants of 0.088, 0.080, 0.045, and 0.040 h-1 for polydisperse, 50, 100, and 200 nm monodisperse aerosols, respectively. The NO2 photolysis rate can be adjusted from 0 to 0.62 min-1. The irradiance spectrum is centered at either 350 or 365 nm, and the maximum irradiance, produced by up to 160 blacklight lamps, is 29.7 W m-2, which corresponds to the ultraviolet (UV) irradiance in Central Finland at noon on a sunny day in the midsummer. The temperature inside the chamber is uniform and can be kept at 25±1 °C. The chamber is kept in an overpressure with a moving top frame, which reduces sample dilution and entrance of contamination during an experiment. The functionality of the chamber was tested with oxidation experiments of toluene, resulting in secondary organic aerosol (SOA) yields of 12-42%, depending on the initial conditions, such as NOx concentration and UV irradiation. The highest gaseous oxidation product yields of 12.4-19.5% and 5.8-19.5% were detected with ions corresponding to methyl glyoxal (m/z 73.029) and 4-oxo-2-pentenal (m/z 99.044), respectively. Overall, reasonable yields of SOA and gaseous reaction products, comparable to those obtained in other laboratories, were obtained.

  12. Internal combustion engine with rotary combustion chamber

    Microsoft Academic Search

    C. N. Hansen; P. C. Cross

    1988-01-01

    This patent describes an internal combustion engine comprising: a block having at least one cylindrical wall surrounding a piston chamber, piston means located in the piston chamber, means operable to reciprocate the piston means in the chamber, head means mounted on the block covering the chamber. The head means having an air and fuel intake passage, an exhaust gas passage,

  13. Internal combustion engine with rotary combustion chamber

    Microsoft Academic Search

    C. N. Hansen; P. C. Cross

    1986-01-01

    This patent describes an internal combustion engine comprising: a block having at least one cylindrical wall surrounding a piston chamber, piston means located in the piston chamber means operable to reciprocate the piston means in the chamber, head means mounted on the block covering the chamber. The head means has an air and fuel intake passage, and exhaust gas passage,

  14. Combustion chamber for internal combustion engines

    Microsoft Academic Search

    Kawamura

    1988-01-01

    A combustion chamber for internal combustion engines, of the type including means for producing swirl within the combustion chamber is described comprising: a combustion chamber provided in the head portion of a piston in the form of a cavity recessed in the axial direction of the piston; fuel injection nozzle means disposed in the combustion chamber and positioned eccentrically with

  15. Combustion chamber for internal combustion engines

    Microsoft Academic Search

    N. Yanagisawa; Y. Sato

    1989-01-01

    A combustion chamber is described for an internal combustion engine, comprising: a main combustion chamber defined by a recess in the top of a piston of the engine, the main combustion chamber being formed with its opening diameter progressively enlarged downwards in the axial direction of the main combustion chamber, and a lip part formed along the periphery of the

  16. Iridium-Coated Rhenium Combustion Chamber

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.; Tuffias, Robert H.; Rosenberg, Sanders D.

    1994-01-01

    Iridium-coated rhenium combustion chamber withstands operating temperatures up to 2,200 degrees C. Chamber designed to replace older silicide-coated combustion chamber in small rocket engine. Modified versions of newer chamber could be designed for use on Earth in gas turbines, ramjets, and scramjets.

  17. Wet drift chambers for precise luminosity

    Microsoft Academic Search

    B. E. Anderson; B. W. Kennedy; K. Ahmet; D. J. Attree; G. A. Barraclough; M. J. Cresswell; D. A. Hayes; D. J. Miller; C. Selby; P. Sherwood

    1994-01-01

    A set of high-precision compact drift chambers has been a vital component of the OPAL luminosity monitor since the start of data-taking at LEP. They were augmented in 1992 by the addition of Small Angle Reference Chambers with a very similar design to the original chamber. The performance of the chambers is reviewed, highlighting both the importance of using polyalkylene

  18. 63. Interior view, kitchen chamber, north elevation. The kitchen chamber ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    63. Interior view, kitchen chamber, north elevation. The kitchen chamber was completed in the first stages of phase III construction. The paneled wall to the fireplace's right displays a phase III molding profile. The mark between the cabinet doors and on the large lower panel indicates the former position of a partition wall. The chimney-breast paneling bears a phase I profile and might have been moved to the room when the fireplace mass in the hall was reduced. - John Bartram House & Garden, House, 54th Street & Lindbergh Boulevard, Philadelphia, Philadelphia County, PA

  19. Thermal System Upgrade of the Space Environment Simulation Test Chamber

    NASA Technical Reports Server (NTRS)

    Desai, Ashok B.

    1997-01-01

    The paper deals with the refurbishing and upgrade of the thermal system for the existing thermal vacuum test facility, the Space Environment Simulator, at NASA's Goddard Space Flight Center. The chamber is the largest such facility at the center. This upgrade is the third phase of the long range upgrade of the chamber that has been underway for last few years. The first phase dealt with its vacuum system, the second phase involved the GHe subsystem. The paper describes the considerations of design philosophy options for the thermal system; approaches taken and methodology applied, in the evaluation of the remaining "life" in the chamber shrouds and related equipment by conducting special tests and studies; feasibility and extent of automation, using computer interfaces and Programmable Logic Controllers in the control system and finally, matching the old components to the new ones into an integrated, highly reliable and cost effective thermal system for the facility. This is a multi-year project just started and the paper deals mainly with the plans and approaches to implement the project successfully within schedule and costs.

  20. Annular-Cross-Section CFE Chamber

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

  1. Impedances of Laminated Vacuum Chambers

    SciTech Connect

    Burov, A.; Lebedev, V.; /Fermilab

    2011-06-22

    First publications on impedance of laminated vacuum chambers are related to early 70s: those are of S. C. Snowdon [1] and of A. G. Ruggiero [2]; fifteen years later, a revision paper of R. Gluckstern appeared [3]. All the publications were presented as Fermilab preprints, and there is no surprise in that: the Fermilab Booster has its laminated magnets open to the beam. Being in a reasonable mutual agreement, these publications were all devoted to the longitudinal impedance of round vacuum chambers. The transverse impedance and the flat geometry case were addressed in more recent paper of K. Y. Ng [4]. The latest calculations of A. Macridin et al. [5] revealed some disagreement with Ref. [4]; this fact stimulated us to get our own results on that matter. Longitudinal and transverse impendances are derived for round and flat laminated vacuum chambers. Results of this paper agree with Ref. [5].

  2. Regional Chamber of Commerce, Roanoke Regional Chamber of

    E-print Network

    Virginia Tech

    Roanoke, Lynchburg, and the New River Valley on the `learning edge.'" "Shaka" has many meanings of economic development and chamber leaders from Roanoke, Lynchburg, and the New River Valley? You can create Education Center www.reynoldshomestead.vt.edu emily Dickinson fever hits Patrick County The Big Read

  3. CHAMBERS FERRY ROADLESS AREA, TEXAS.

    USGS Publications Warehouse

    Houser, B.B.; Ryan, George S.

    1984-01-01

    A geologic and geochemical investigation of the Chambers Ferry Roadless Area, Texas was conducted. The area has probable mineral-resource potential for oil and gas and for lignite. No metallic or additional energy resources were identified in the investigation. Detailed analyses of well logs from the vicinity of the Chambers Ferry Roadless Area, in conjunction with seismic data, are necessary to determine if the subsurface stratigraphy and structure are favorable for the accumulation of oil and gas. A shallow drilling program involving coring on a close-space grid is necessary for determination of the rank and continuity of seams of lignitic sediments in the area.

  4. Open-chamber combustion study

    NASA Astrophysics Data System (ADS)

    Meyers, D. P.; Meyer, R. C.

    1994-04-01

    The test program was undertaken to research trade-offs between engine design and operational parameters on open-chamber, premixed spark-ignited gas engines, with a primary focus on combustion effects. This included combustion chamber designs which are conceptually diametrically opposed -- a high squish design typical of diesel engines and a virtually quiescent design. The reader should note that these data are somewhat abstract compared to conventional engines, because the Labeco test engine has exceptionally high friction and the lean-burn data were run unboosted.

  5. The Mark III vertex chamber

    SciTech Connect

    Adler, J.; Bolton, T.; Bunnell, K.; Cassell, R.; Cheu, E.; Freese, T.; Grab, C.; Mazaheri, G.; Mir, R.; Odian, A.

    1987-07-01

    The design and construction of the new Mark III vertex chamber is described. Initial tests with cosmic rays prove the ability of track reconstruction and yield triplet resolutions below 50 ..mu..m at 3 atm using argon/ethane (50:50). Also performed are studies using a prototype of a pressurized wire vertex chamber with 8 mm diameter straw geometry. Spatial resolution of 35mm was obtained using dimethyl ether (DME) at 1 atm and 30 ..mu..m using argon/ethane (50/50 mixture) at 4 atm. Preliminary studies indicate the DME to adversely affect such materials as aluminized Mylar and Delrin.

  6. Gas-Grain Simulation Facility (GGSF)

    NASA Technical Reports Server (NTRS)

    Greenwald, Ken

    1992-01-01

    The goal of the Gas-Grain Simulation Facility project is to provide a microgravity laboratory to facilitate research relevant to exobiology (the study of the origin and evolution of life in the universe). Such a facility will also be useful in other areas of study important to NASA including planetary science, biology, atmospheric science, astrophysics, chemistry, and physics. To achieve this goal, the project will develop and support the GGSF, a modular facility-class payload planned for inclusion on Space Station Freedom. The GGSF will consist of the following: an experiment chamber(s) supported by subsystems that provide chamber environment regulation and monitoring capabilities; sample generation, injection, positioning, and retrieval capabilities; and computer control, data acquisition, and housekeeping capabilities. The facility will also provide analytical tools such as light-scattering measurement systems, aerosol size-spectrum measurement devices, and optical imaging systems.

  7. Lightweight Chambers for Thrust Assemblies

    NASA Technical Reports Server (NTRS)

    Elam, Sandra K.; Lee, Jonathan; Holmes, Richard; Zimmerman, Frank; Effinger, Mike; Turner, James E. (Technical Monitor)

    2001-01-01

    The Marshall Space Flight Center (MSFC) of the National Aeronautics and Space Administration (NASA) has successfully applied new materials and fabrication techniques to create actively cooled thrust chambers that operate 200-400 degrees hotter and weigh 50% lighter than conventional designs. In some vehicles, thrust assemblies account for as much as 20% of the engine weight. So, reducing the weight of these components and increasing their operating range will benefit many engines and vehicle designs, including Reusable Launch Vehicle (RLV) concepts. Obviously, copper and steel alloys have been used successfully for many years in the chamber components of thrust assemblies. Yet, by replacing the steel alloys with Polymer Matrix Composite (PMC) and/or Metal Matrix Composite (MMC) materials, design weights can be drastically reduced. In addition, replacing the traditional copper alloys with a Ceramic Matrix Composite (CMC) or an advanced copper alloy (Cu-8Cr-4Nb, also known as GRCop-84) significantly increases allowable operating temperatures. Several small MMC and PMC demonstration chambers have recently been fabricated with promising results. Each of these designs included GRCop-84 for the cooled chamber liner. These units successfully verified that designs over 50% lighter are feasible. New fabrication processes, including advanced casting technology and a low cost vacuum plasma spray (VPS) process, were also demonstrated with these units. Hot-fire testing at MSFC is currently being conducted on the chambers to verify increased operating temperatures available with the GRCop-84 liner. Unique CMC chamber liners were also successfully fabricated and prepared for hot-fire testing. Yet, early results indicate these CMC liners need significantly more development in order to use them in required chamber designs. Based on the successful efforts with the MMC and PMC concepts, two full size "lightweight" chambers are currently being designed and fabricated for hot-fire testing at MSFC in 2001. These "full size" chambers will be similar in size to those used on the X33 engine (RS2200). One will be fabricated with a MMC structural jacket, while the other uses a PMC jacket. Each will be designed for thrust levels of 15,000 pounds in an oxygen/hydrogen environment with liquid hydrogen coolant. Both chambers will use GRCop-84 for its channel wall liner. Each unit is expected to be at least 60% lighter than a conventional design with traditional materials. Hot-fire testing on the full size units in late 2001 will directly compare performance results between a conventional chamber design and these "lightweight" alternatives. The technology developed and demonstrated by this effort will not only benefit next generation RLV programs, but it can be applied to other existing and future engine programs, as well. Efforts were sponsored by the Advanced Space Transportation Program for RLV Focused Technologies. The task team was led by MSFC with additional members from NASA-Glenn Research Center and the Rocketdyne Division of The Boeing Company. Specific materials development and fabrication processes were provided by Aerojet, Lockheed Martin Astronautics, Composite Optics, Inc., Hyper-Therm, Ceramic Composites, Inc., MSE Technology Applications, and Plasma Processes, Inc.

  8. BOREAS TGB-1 NSA CH4 and CO2 Chamber Flux Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Crill, Patrick; Varner, Ruth K.

    2000-01-01

    The BOREAS TGB-1 team made methane (CH4) and carbon dioxide (CO2) dark chamber flux measurements at the NSA-OJP, NSA-OBS, NSA-BP, and NSA-YJP sites from 16-May-1994 through 13-Sep-1994. Gas samples were extracted approximately every 7 days from dark chambers and analyzed at the NSA lab facility. The data are provided in tabular ASCII files.

  9. Operation of limited streamer mode production-line chambers with non-flammable gases

    NASA Astrophysics Data System (ADS)

    Hungerford, Dale; Lau, Kwong; Liu, Jianxiong; Mo, Guang-Hui; Parks, Drew; Pyrlik, Jörg; Sanders, David; Weinstein, Roy; Pei-Ruo, Shen; Xiu-Zhen, Yu

    1990-01-01

    Plateaus for two non-flammable gas mixtures have been studied on a statistically meaningful batch of limited streamer mode production-line chambers. These were produced at the Streamer Chamber Assembly and Research Facility (SCARF) in Houston. Useful plateaus were found on all 35 of the randomly selected chambers for a gas composed of 88% CO 2 + 10% isobutane + 2% neon, with plateua width of 470±72 V, and a gas composed of 88% CO 2 + 10% isobutane + 2% argon, with a plateau width of 543±80 V. Chambers operated with a standard gas mixture of 75% isobutane + 25% Ar show much longer plateaus, 943±311 V, with the plateau limit set by the individual chamber quality, whereas plateaus using the non-flammable gases are found to be gas limited.

  10. The TESLA Time Projection Chamber

    E-print Network

    Nabil Ghodbane

    2002-12-12

    A large Time Projection Chamber is proposed as part of the tracking system for a detector at the TESLA electron positron linear collider. Different ongoing R&D studies are reviewed, stressing progress made on a new type readout technique based on Micro-Pattern Gas Detectors.

  11. MFE Chamber Overview Mohamed Abdou

    E-print Network

    Abdou, Mohamed

    the world program confirming US results on testing requirements and the effectiveness/importance of VNS, and environmental attractiveness of fusion energy systems #12;The US Chamber Technology Program has established of Creative Innovations - LW testing in NSTX - Materials - Heat Transfer and other analysis - Objectives

  12. Chamber Clearing First Principles Modeling

    SciTech Connect

    Loosmore, G

    2009-06-09

    LIFE fusion is designed to generate 37.5 MJ of energy per shot, at 13.3 Hz, for a total average fusion power of 500 MW. The energy from each shot is partitioned among neutrons ({approx}78%), x-rays ({approx}12%), and ions ({approx}10%). First wall heating is dominated by x-rays and debris because the neutron mean free path is much longer than the wall thickness. Ion implantation in the first wall also causes damage such as blistering if not prevented. To moderate the peak-pulse heating, the LIFE fusion chamber is filled with a gas (such as xenon) to reduce the peak-pulse heat load. The debris ions and majority of the x-rays stop in the gas, which re-radiates this energy over a longer timescale (allowing time for heat conduction to cool the first wall sufficiently to avoid damage). After a shot, because of the x-ray and ion deposition, the chamber fill gas is hot and turbulent and contains debris ions. The debris needs to be removed. The ions increase the gas density, may cluster or form aerosols, and can interfere with the propagation of the laser beams to the target for the next shot. Moreover, the tritium and high-Z hohlraum debris needs to be recovered for reuse. Additionally, the cryogenic target needs to survive transport through the gas mixture to the chamber center. Hence, it will be necessary to clear the chamber of the hot contaminated gas mixture and refill it with a cool, clean gas between shots. The refilling process may create density gradients that could interfere with beam propagation, so the fluid dynamics must be studied carefully. This paper describes an analytic modeling effort to study the clearing and refilling process for the LIFE fusion chamber. The models used here are derived from first principles and balances of mass and energy, with the intent of providing a first estimate of clearing rates, clearing times, fractional removal of ions, equilibrated chamber temperatures, and equilibrated ion concentrations for the chamber. These can be used to scope the overall problem and provide input to further studies using fluid dynamics and other more sophisticated tools.

  13. Design and testing of a model CELSS chamber robot

    NASA Technical Reports Server (NTRS)

    Davis, Mark; Dezego, Shawn; Jones, Kinzy; Kewley, Christopher; Langlais, Mike; Mccarthy, John; Penny, Damon; Bonner, Tom; Funderburke, C. Ashley; Hailey, Ruth

    1994-01-01

    A robot system for use in an enclosed environment was designed and tested. The conceptual design will be used to assist in research performed by the Controlled Ecological Life Support System (CELSS) project. Design specifications include maximum load capacity, operation at specified environmental conditions, low maintenance, and safety. The robot system must not be hazardous to the sealed environment, and be capable of stowing and deploying within a minimum area of the CELSS chamber facility. This design consists of a telescoping robot arm that slides vertically on a shaft positioned in the center of the CELSS chamber. The telescoping robot arm consists of a series of links which can be fully extended to a length equal to the radius of the working envelope of the CELSS chamber. The vertical motion of the robot arm is achieved through the use of a combination ball screw/ball spline actuator system. The robot arm rotates cylindrically about the vertical axis through use of a turntable bearing attached to a central mounting structure fitted to the actuator shaft. The shaft is installed in an overhead rail system allowing the entire structure to be stowed and deployed within the CELSS chamber. The overhead rail system is located above the chamber's upper lamps and extends to the center of the CELSS chamber. The mounting interface of the actuator shaft and rail system allows the entire actuator shaft to be detached and removed from the CELSS chamber. When the actuator shaft is deployed, it is held fixed at the bottom of the chamber by placing a square knob on the bottom of the shaft into a recessed square fitting in the bottom of the chamber floor. A support boot ensures the rigidity of the shaft. Three student teams combined into one group designed a model of the CELSS chamber robot that they could build. They investigated materials, availability, and strength in their design. After the model arm and stand were built, the class performed pre-tests on the entire system. A stability pre-test was used to determine whether the model robot arm would tip over on the stand when it was fully extended. Results showed the stand tipped when 50 Newtons were applied horizontally to the top of the vertical shaft while the arm was fully extended. This proved that it was stable. Another pre-test was the actuator slip test used to determine if there is an adequate coefficient of friction between the actuator drive wheels and drive cable to enable the actuator to fully extend and retract the arm. This pre-test revealed that the coefficient of friction was not large enough to prevent slippage. Sandpaper was glued to the drive wheel and this eliminated the slippage problem. The class preformed a fit test in the CELSS chamber to ensure that the completed robot arm is capable of reaching the entire working envelope. The robot was centered in the chamber and the arm was fully extended to the sides of the chamber. The arm was also able to retract to clear the drain pipes separating the upper and lower plant trays.

  14. Design and testing of a model CELSS chamber robot

    NASA Astrophysics Data System (ADS)

    Davis, Mark; Dezego, Shawn; Jones, Kinzy; Kewley, Christopher; Langlais, Mike; McCarthy, John; Penny, Damon; Bonner, Tom; Funderburke, C. Ashley; Hailey, Ruth

    1994-08-01

    A robot system for use in an enclosed environment was designed and tested. The conceptual design will be used to assist in research performed by the Controlled Ecological Life Support System (CELSS) project. Design specifications include maximum load capacity, operation at specified environmental conditions, low maintenance, and safety. The robot system must not be hazardous to the sealed environment, and be capable of stowing and deploying within a minimum area of the CELSS chamber facility. This design consists of a telescoping robot arm that slides vertically on a shaft positioned in the center of the CELSS chamber. The telescoping robot arm consists of a series of links which can be fully extended to a length equal to the radius of the working envelope of the CELSS chamber. The vertical motion of the robot arm is achieved through the use of a combination ball screw/ball spline actuator system. The robot arm rotates cylindrically about the vertical axis through use of a turntable bearing attached to a central mounting structure fitted to the actuator shaft. The shaft is installed in an overhead rail system allowing the entire structure to be stowed and deployed within the CELSS chamber. The overhead rail system is located above the chamber's upper lamps and extends to the center of the CELSS chamber. The mounting interface of the actuator shaft and rail system allows the entire actuator shaft to be detached and removed from the CELSS chamber. When the actuator shaft is deployed, it is held fixed at the bottom of the chamber by placing a square knob on the bottom of the shaft into a recessed square fitting in the bottom of the chamber floor. A support boot ensures the rigidity of the shaft. Three student teams combined into one group designed a model of the CELSS chamber robot that they could build. They investigated materials, availability, and strength in their design. After the model arm and stand were built, the class performed pre-tests on the entire system. A stability pre-test was used to determine whether the model robot arm would tip over on the stand when it was fully extended. Results showed the stand tipped when 50 Newtons were applied horizontally to the top of the vertical shaft while the arm was fully extended. chamber to ensure that the completed robot arm is capable of reaching the entire working envelope. -The robot was centered in the chamber and the arm was fully extended to the sides of the chamber. The arm was also able to retract to clear the drain pipes separating the upper and lower plant trays.

  15. Scene projection developments in the AEDC space simulation chambers

    NASA Astrophysics Data System (ADS)

    Lowry, H. S., III; Crider, D. H.; Goethert, W. H.; Bertrand, W. T.; Steely, S. L.

    2005-05-01

    Testing system performance early and often under flight conditions is fundamental to managing uncertainty in system performance predictions and reducing system life-cycle cost. As a Department of Defense (DoD) Major Range Test Facility Base (MRTFB), Arnold Engineering Development Center (AEDC) strives to ensure that DoD system performance tests are not limited by test and evaluation capabilities. For over 30 years, the space chambers at AEDC have performed space sensor characterization, calibration, and mission simulation testing on space-based, interceptor, and air-borne sensors. In partnership with the Missile Defense Agency (MDA), AEDC continuously pursues capability upgrades in order to keep pace with evolving sensor technologies. Upgrades to sensor test facilities require rigorous facility characterization and calibration efforts, all of which are routinely included in AEDC's annual activities to ensure quality test data. This paper discusses the status of such upgrades especially with regard to scene projection.

  16. Building a Cloud Chamber (Cosmic Ray Detector)

    NSDL National Science Digital Library

    In this activity, students learn about cosmic rays firsthand by building a cloud chamber to detect them. The comprehensive activity includes step-by-step directions for constructing and operating a cloud chamber and ideas for additional experiments.

  17. Single wire drift chamber design

    SciTech Connect

    Krider, J.

    1987-03-30

    This report summarizes the design and prototype tests of single wire drift chambers to be used in Fermilab test beam lines. The goal is to build simple, reliable detectors which require a minimum of electronics. Spatial resolution should match the 300 ..mu..m rms resolution of the 1 mm proportional chambers that they will replace. The detectors will be used in beams with particle rates up to 20 KHz. Single track efficiency should be at least 99%. The first application will be in the MT beamline, which has been designed for calibration of CDF detectors. A set of four x-y modules will be used to track and measure the momentum of beam particles.

  18. Acoustic noise control using multiple expansion chambers

    NASA Astrophysics Data System (ADS)

    Horoub, Mamon Mohammad

    Silencers with expansion chambers are often used to reduce noise in different applications such as HVAC, exhaust systems, and car muffler systems. This study focuses on the effectiveness of multiple expansion chambers in reducing noise. Methods for enhancing silencer designs are realized by utilizing extended tubes, changing expansion chamber cross sectional areas and changing the lengths of the expansion chambers and connecting tubes. General guidelines for design enhancement are provided through this study.

  19. The LIFE Dynamic Chamber System

    NASA Astrophysics Data System (ADS)

    Rhodes, Mark; Kane, Jave; Latkowski, Jeffery; Cook, Andrew; Divol, Laurent; Loosmore, Gwendolen; Scott, Howard; Scullard, Christian; Tabak, Max; Wilks, Scott; Moses, Gregory; Heltemes, Thad; Sacks, Ryan; Pantano, Carlos; Kramer, Richard

    2011-10-01

    Dry-wall IFE designs such as LIFE utilize Xe fill gas to protect the target chamber first wall from x-ray heating and ionic debris. A key question is how cool, settled and clean the Xe must be to permit beam propagation and target transport, and how to reach this state at a 10+ Hz shot repetition rate. Xe is at low density in the target chamber, and purified Xe is reinjected at higher density and lower temperature into the larger outer chamber. Maintenance of this density difference due to blast waves generated by implosion of the target capsules is being assessed with HYDRA and 3D VTF, and possible validation experiments are being investigated. Detailed gas response near the wall is being studied using 3D Miranda. A laboratory-scale theta pinch experiment will study cooling and beam propagation in Xe. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  20. Recent Advances in Chamber Science and Technology

    E-print Network

    Abdou, Mohamed

    Recent Advances in Chamber Science and Technology Mohamed Abdou April 8, 2002ISFNT-6 San Diego, USA #12;Recent Advances in Chamber Science & Technology OutlineOutline · Highlights of Major World - Experiments - Analysis & Design #12;Highlights of Major World Programs on Chamber (Blanket) Technology

  1. Delay-line readout drift chambers

    NASA Astrophysics Data System (ADS)

    Atencio, L. G.; Amann, J. F.; Boudrie, R. L.; Morris, C. L.

    Delay-line readout multiwire gas proportional chambers have been constructed that use drift time information to interpolate between anode wires. Position resolutions over the entire active area of the chamber of 150 ?m fwhm are routinely obtained for instantaneous event rates of up to 1 MHz. Chambers with active areas of up to 30 cm by 90 cm have been built.

  2. A Sensitive Cloud Chamber without Radioactive Sources

    ERIC Educational Resources Information Center

    Zeze, Syoji; Itoh, Akio; Oyama, Ayu; Takahashi, Haruka

    2012-01-01

    We present a sensitive diffusion cloud chamber which does not require any radioactive sources. A major difference from commonly used chambers is the use of a heat sink as its bottom plate. The result of a performance test of the chamber is given. (Contains 8 figures.)

  3. Simple cloud chambers using gel ice packs

    Microsoft Academic Search

    Masahiro Kamata; Miki Kubota

    2012-01-01

    Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry ice or liquid nitrogen. The

  4. Simple Cloud Chambers Using Gel Ice Packs

    ERIC Educational Resources Information Center

    Kamata, Masahiro; Kubota, Miki

    2012-01-01

    Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

  5. Flow-induced noise from wind tunnel turbulence reduction screens

    Microsoft Academic Search

    Richard M. Allen; Richard R. Gibbs; Patrick J. F. Clark

    1987-01-01

    Boeing is acquiring a new Low Speed Aeroacoustic Facility to simulate low speed flight conditions by adding a free jet to an existing anechoic chamber. The primary facility characteristics will be high flow quality and low background noise levels in the open jet test section. During the design phase, it was recognized that noise generated by flow through the turbulence

  6. Hydrocarbon-fuel/combustion-chamber-liner materials compatibility

    NASA Technical Reports Server (NTRS)

    Gage, Mark L.

    1990-01-01

    Results of material compatibility experiments using hydrocarbon fuels in contact with copper-based combustion chamber liner materials are presented. Mil-Spec RP-1, n- dodecane, propane, and methane fuels were tested in contact with OFHC, NASA-Z, and ZrCu coppers. Two distinct test methods were employed. Static tests, in which copper coupons were exposed to fuel for long durations at constant temperature and pressure, provided compatibility data in a precisely controlled environment. Dynamic tests, using the Aerojet Carbothermal Test Facility, provided fuel and copper compatibility data under realistic booster engine service conditions. Tests were conducted using very pure grades of each fuel and fuels to which a contaminant, e.g., ethylene or methyl mercaptan, was added to define the role played by fuel impurities. Conclusions are reached as to degradation mechanisms and effects, methods for the elimination of these mechanisms, selection of copper alloy combustion chamber liners, and hydrocarbon fuel purchase specifications.

  7. Status of the construction of the Gluex Forward Drift Chambers

    NASA Astrophysics Data System (ADS)

    Taylor, Simon

    2013-04-01

    Currently under construction at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia, the full GlueX detector is designed to study gluonic degrees of freedom through the production of ``hybrid'' mesons with exotic quantum numbers. To accomplish this task the detector requires high acceptance and reasonably good resolution for both charged and neutral particles. The core of the detector is housed within the bore of a 2.0 Tesla solenoidal magnet. Charged particles emanating from the target for angles greater than about 20 degrees with respect to the beam line will be tracked with a straw-tube detector (the Central Drift Chamber). Forward-going charged particles will be detected using the Forward Drift Chambers (FDC). I will describe the design and construction of the FDC and present preliminary resolution measurements.

  8. Canister Decontamination Chamber No. 1 operability test results

    SciTech Connect

    Magoulas, V.E.

    1987-10-30

    The DWPF Canister Decontamination Chamber No. 1 (CDC) was installed at the TNX facility in October, 1986 for operability testing. Operability testing was required because this equipment is unique and is a critical part of the defense waste process. The test was successful in demonstrating the canister decontamination operation. Testing verified proper nozzle locations, frit suspension, level probe and CCTV operations. The following recommendations are based on data obtained from frit blasting 24 canisters: reduce the recirculation pump speed, to allow proper level probes operation; add an extension to the chamber rinse nozzle which allows removal of frit from the top of the upper guide rinse nozzle; increase visibility through the CCTV camera; make the CMM grapple jaw pins more compatible with the MSM; and improve canister guide capability to aid in canister loading. CDC Operability Testing was completed October, 1987. 6 refs., 11 figs., 2 tabs.

  9. Space power facility readiness for Space Station power system testing

    Microsoft Academic Search

    Roger L. Smith

    1995-01-01

    This document provides information which shows that the NASA Lewis Research Center's Space Power Facility (SPF) will be ready to execute the Space Station electric power system thermal vacuum chamber testing. The SPF is located at LeRC West (formerly the Plum Brook Station), Sandusky, Ohio. The SPF is the largest space environmental chamber in the world, having an inside horizontal

  10. THE MOBILE WINDOW THERMAL TEST FACILITY (MoWiTT)

    E-print Network

    Klems, J. H.

    2011-01-01

    Window Thermal Test Facility Instrumentation. (b) chambersthermal cycle. Therefore a dynamic modeling of the chamberthermal performance of small, high performance windows necessi- tates very accurate determination of the losses through the test chamber

  11. Optical testing cryogenic thermal vacuum facility

    NASA Astrophysics Data System (ADS)

    Dohogne, Patrick W.; Carpenter, Warren A.

    1990-11-01

    The construction of a turnkey cryogenic vacuum test facility was recently completed. The facility will be used to measure and record the surface profile of large diameter and 540 kg optics under simulated space conditions. The vacuum test chamber is a vertical stainless steel cylinder with a 3.5 diameter and a 7 m tangent length. The chamber was designed to maximize optical testing quality by minimizing the vibrations between the laser interferometer and the test specimen. This was accomplished by designing the chamber for a high natural frequency and vibration isolating the chamber. An optical test specimen is mounted on a movable presentation stage. During thermal vacuum testing, the specimen may be positioned to + or - 0.00025 cm accuracy with a fine adjustment mechanism. The chamber is evacuated by a close coupled Roots-type blower and rotary vane pump package and two cryopumps. The chamber is equipped with an optically dense gaseous nitrogen cooled thermal shroud. The thermal shroud is used to cool or warm the optical test specimen at a controlled rate. A control system is provided to automatically evacuate the chamber and cooldown the test specimen to the selected control temperature.

  12. Optical testing cryogenic thermal vacuum facility

    NASA Technical Reports Server (NTRS)

    Dohogne, Patrick W.; Carpenter, Warren A.

    1990-01-01

    The construction of a turnkey cryogenic vacuum test facility was recently completed. The facility will be used to measure and record the surface profile of large diameter and 540 kg optics under simulated space conditions. The vacuum test chamber is a vertical stainless steel cylinder with a 3.5 diameter and a 7 m tangent length. The chamber was designed to maximize optical testing quality by minimizing the vibrations between the laser interferometer and the test specimen. This was accomplished by designing the chamber for a high natural frequency and vibration isolating the chamber. An optical test specimen is mounted on a movable presentation stage. During thermal vacuum testing, the specimen may be positioned to + or - 0.00025 cm accuracy with a fine adjustment mechanism. The chamber is evacuated by a close coupled Roots-type blower and rotary vane pump package and two cryopumps. The chamber is equipped with an optically dense gaseous nitrogen cooled thermal shroud. The thermal shroud is used to cool or warm the optical test specimen at a controlled rate. A control system is provided to automatically evacuate the chamber and cooldown the test specimen to the selected control temperature.

  13. Facility Microgrids

    SciTech Connect

    Ye, Z.; Walling, R.; Miller, N.; Du, P.; Nelson, K.

    2005-05-01

    Microgrids are receiving a considerable interest from the power industry, partly because their business and technical structure shows promise as a means of taking full advantage of distributed generation. This report investigates three issues associated with facility microgrids: (1) Multiple-distributed generation facility microgrids' unintentional islanding protection, (2) Facility microgrids' response to bulk grid disturbances, and (3) Facility microgrids' intentional islanding.

  14. Thrust chamber material technology program

    NASA Technical Reports Server (NTRS)

    Andrus, J. S.; Bordeau, R. G.

    1989-01-01

    This report covers work performed at Pratt & Whitney on development of copper-based materials for long-life, reusable, regeneratively cooled rocket engine thrust chambers. The program approached the goal of enhanced cyclic life through the application of rapid solidification to alloy development, to introduce fine dispersions to strengthen and stabilize the alloys at elevated temperatures. After screening of alloy systems, copper-based alloys containing Cr, Co, Hf, Ag, Ti, and Zr were processed by rapid-solidification atomization in bulk quantities. Those bulk alloys showing the most promise were characterized by tensile testing, thermal conductivity testing, and elevated-temperature, low-cycle fatigue (LFC) testing. Characterization indicated that Cu- 1.1 percent Hf exhibited the greatest potential as an improved-life thrust chamber material, exhibiting LCF life about four times that of NASA-Z. Other alloys (Cu- 0.6 percent Zr, and Cu- 0.6 percent Zr- 1.0 percent Cr) exhibited promise for use in this application, but needed more development work to balance properties.

  15. Numerical simulation of detonation processes in a variable cross-section chamber

    E-print Network

    Texas at Arlington, University of

    facilities [2]. The pri- mary advantage of detonation combustion as com- pared to deflagration is its rapid in a combustion chamber with variable cross- sections are numerically simulated for a hydrogen­air reacting flow considerable inter- est for certain applications, such as in propulsion [1] and in high-enthalpy ground test

  16. EVALUATION OF THE FLUX CHAMBER METHOD FOR MEASURING VOLATILE ORGANIC EMISSIONS FROM SURFACE IMPOUNDMENTS

    EPA Science Inventory

    This research deals with the validation of the flux chamber method for measuring volatile organic emissions from liquid surfaces in treatment, storage and disposal facilities (TSDF). A simulated surface impoundment was constructed so that method precision and accuracy could be de...

  17. FULL-SCALE CHAMBER INVESTIGATION AND SIMULATION OF AIR FRESHENER EMISSIONS IN THE PRESENCE OF OZONE

    EPA Science Inventory

    The paper discusses results of tests, conducted in the EPA large chamber facility, determining emissions and chemical degradation of volatile organic compounds (VOCs) from one electrical plug-in type pine-scented air freshener in the presence of ozone supplied by a device markete...

  18. OUTDOOR SMOG CHAMBER EXPERIMENTS TO TEST PHOTOCHEMICAL MODELS: MICROFICHE OF DATA COLLECTED IN THE STUDY

    EPA Science Inventory

    The smog chamber facility of the University of North Carolina was used in a study to collect experimental data for developing and testing kinetic mechanisms of photochemical smog formation. Listings and plots of the 115 dual all-day experiments conducted in the study are containe...

  19. MEASUREMENT OF GASEOUS EMISSION RATES FROM LAND SURFACES USING AN EMISSION ISOLATION FLUX CHAMBER. USER'S GUIDE

    EPA Science Inventory

    A promising method for monitoring ground emissions involves the use of an emission isolation flux chamber. The method is simple, easily available, and inexpensive. Applications would include RCRA and CERCLA facilities. To date, a uniform method operations does not exist. For this...

  20. 30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Access to drying chambers, hot gas inlet chambers and ductwork; installation...77.305 Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot gas inlet chambers and all ductwork in...

  1. 30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Access to drying chambers, hot gas inlet chambers and ductwork; installation...77.305 Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot gas inlet chambers and all ductwork in...

  2. 30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Access to drying chambers, hot gas inlet chambers and ductwork; installation...77.305 Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot gas inlet chambers and all ductwork in...

  3. 30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Access to drying chambers, hot gas inlet chambers and ductwork; installation...77.305 Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot gas inlet chambers and all ductwork in...

  4. 30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Access to drying chambers, hot gas inlet chambers and ductwork; installation...77.305 Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot gas inlet chambers and all ductwork in...

  5. Fluidized wall for protecting fusion chamber walls

    DOEpatents

    Maniscalco, James A. (Danville, CA); Meier, Wayne R. (Livermore, CA)

    1982-01-01

    Apparatus for protecting the inner wall of a fusion chamber from microexplosion debris, x-rays, neutrons, etc. produced by deuterium-tritium (DT) targets imploded within the fusion chamber. The apparatus utilizes a fluidized wall similar to a waterfall comprising liquid lithium or solid pellets of lithium-ceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.

  6. Experimental investigation of a lightweight rocket chamber

    NASA Technical Reports Server (NTRS)

    Dalgleish, John E; Tischler, Adelbert O

    1953-01-01

    Experiments have been conducted with a jacketed rocket combustion chamber that was fabricated by hydraulic-forming from sheet metal. Rocket combustion chambers made by this method have been used successfully. Runs with these combustion chambers have been made at over-all heat-transfer rates 1.7 Btu per square inch per second with water cooling and also ammonia as a regenerative coolant.

  7. Drift chamber tracking with neural networks

    SciTech Connect

    Lindsey, C.S.; Denby, B.; Haggerty, H.

    1992-10-01

    We discuss drift chamber tracking with a commercial log VLSI neural network chip. Voltages proportional to the drift times in a 4-layer drift chamber were presented to the Intel ETANN chip. The network was trained to provide the intercept and slope of straight tracks traversing the chamber. The outputs were recorded and later compared off line to conventional track fits. Two types of network architectures were studied. Applications of neural network tracking to high energy physics detector triggers is discussed.

  8. Free-Flow Open-Chamber Electrophoresis

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Free-flow open-chamber electrophoresis variant of free-flow electrophoresis performed in chamber with open ends and in which velocity of electro-osmotic flow adjusted equal to and opposite mean electrophoretic velocity of sample. Particles having electrophoretic mobilities greater than mean mobility of sample particles move toward cathode, those with mobilities less move toward anode. Technique applied to separation of components of mixtures of biologically important substances. Sensitivity enhanced by use of tapered chamber.

  9. LAYOUT AND SIZING OF ESF ALCOVES AND REFUGE CHAMBERS

    SciTech Connect

    John Beesley and Romeo S. Jurani

    1995-08-25

    The purpose of this analysis is to establish size requirements and approximate locations of Exploratory Studies Facility (ESF) test and operations alcoves, including refuge chambers during construction of the Topopah Spring (TS) loop. Preliminary conceptual layouts for non-deferred test alcoves will be developed to examine construction feasibility based on current test plans and available equipment. The final location and configuration layout for alcoves will be developed when in-situ rock conditions can be visually determined. This will be after the TBM has excavated beyond the alcove location and the rock has been exposed. The analysis will examine the need for construction of walkways and electrical alcoves in the ramps and main drift. Niches that may be required to accommodate conveyor booster drives and alignments are not included in this analysis. The analysis will develop design criteria for refuge chambers to meet MSHA requirements and will examine the strategic location of refuge chambers based on their potential use in various ESF fire scenarios. This document supersedes DI:BABE00000-01717-0200-00003 Rev 01, ''TS North Ramp Alcove and Stubout Location Analysis'' in its entirety (Reference 5-6).

  10. Response of ionization chamber based pocket dosimeter to beta radiation.

    PubMed

    Kumar, Munish; Gupta, Anil; Pradhan, S M; Bakshi, A K; Chougaonkar, M P; Babu, D A R

    2013-12-01

    Quantitative estimate of the response of ionization chamber based pocket dosimeters (DRDs) to various beta sources was performed. It has been established that the ionization chamber based pocket dosimeters do not respond to beta particles having energy (Emax)<1 MeV and same was verified using (147)Pm, (85)Kr and (204)Tl beta sources. However, for beta particles having energy >1 MeV, the DRDs exhibit measureable response and the values are ~8%, ~14% and ~27% per mSv for natural uranium, (90)Sr/(90)Y and (106)Ru/(106)Rh beta sources respectively. As the energy of the beta particles increases, the response also increases. The response of DRDs to beta particles having energy>1 MeV arises due to the fact that the thickness of the chamber walls is less than the maximum range of beta particles. This may also be one of the reasons for disparity between doses measured with passive/legal dosimeters (TLDs) and DRDs in those situations in which radiation workers are exposed to mixed field of gamma photons and beta particles especially at uranium processing plants, nuclear (power and research) reactors, waste management facilities and fuel reprocessing plants etc. The paper provides the reason (technical) for disparity between the doses recorded by TLDs and DRDs in mixed field of photons and beta particles. PMID:23978508

  11. Thrust chamber thermal barrier coating techniques

    NASA Technical Reports Server (NTRS)

    Quentmeyer, Richard J.

    1989-01-01

    Methods for applying thermal barrier coatings to the hot-gas side wall of rocket thrust chambers in order to significantly reduce the heat transfer in high heat flux regions has been the focus of technology efforts for many years. A successful technique developed by NASA-Lewis that starts with the coating on a mandrel and then builds the thrust chamber around it by electroforming appropriate materials is described. This results in a smooth coating with exceptional adherence, as was demonstrated in hot fire rig tests. The low cycle fatigue life of chambers with coatings applied in this manner was increased dramatically compared to uncoated chambers.

  12. Internal combustion engine with rotary combustion chamber

    SciTech Connect

    Hansen, C.N.; Cross, P.C.

    1986-09-23

    This patent describes an internal combustion engine comprising: a block having at least one cylindrical wall surrounding a piston chamber, piston means located in the piston chamber means operable to reciprocate the piston means in the chamber, head means mounted on the block covering the chamber. The head means has an air and fuel intake passage, and exhaust gas passage, a rotary valve assembly operatively associated with the head means for controlling the flow of air and fuel into the rotary valve assembly and piston chamber and the flow of exhaust gas from rotary valve assembly and the piston chamber. The means has a housing with a bore open to the piston chamber accommodating the rotary valve assembly, the valve assembly comprising a cylindrical sleeve located in the bore, the sleeve having an inner surface, an ignition hole, and intake and exhaust ports aligned with the intake passage and exhaust gas passage, spark generating means mounted on the housing operable to generate a spark. The rotatable valving means is located within the sleeve for controlling the flow of air and fuel into the rotary valve assembly and piston chamber and the flow of exhaust gases out of the rotary valve assembly and piston chamber.

  13. Engineering verification of the biomass production chamber

    NASA Technical Reports Server (NTRS)

    Prince, R. P.; Knott, W. M., III; Sager, J. C.; Jones, J. D.

    1992-01-01

    The requirements for life support systems, both biological and physical-chemical, for long-term human attended space missions are under serious study throughout NASA. The KSC 'breadboard' project has focused on biomass production using higher plants for atmospheric regeneration and food production in a special biomass production chamber. This chamber is designed to provide information on food crop growth rate, contaminants in the chamber that alter plant growth requirements for atmospheric regeneration, carbon dioxide consumption, oxygen production, and water utilization. The shape and size, mass, and energy requirements in relation to the overall integrity of the biomass production chamber are under constant study.

  14. Temperature dependence of cavity ionization chamber response

    NASA Astrophysics Data System (ADS)

    Yi, Chul-Young; Kim, Hyun-Moon

    2013-04-01

    The temperature dependence of the cavity ion chamber response was measured at room temperature in the range 17 °C to 27 °C. By analysing the variation of the ionization current with temperature produced in the cavity chamber, the temperature coefficient of the cavity chamber response was evaluated. The values were 4.1 × 10-4 °C-1, 4.3 × 10-4 °C-1 and 2 × 10-5 °C-1 for chambers made of C552 air equivalent plastic, polyoxymethylene and graphite, respectively.

  15. PSL Icing Facility Upgrade Overview

    NASA Technical Reports Server (NTRS)

    Griffin, Thomas A.; Dicki, Dennis J.; Lizanich, Paul J.

    2014-01-01

    The NASA Glenn Research Center Propulsion Systems Lab (PSL) was recently upgraded to perform engine inlet ice crystal testing in an altitude environment. The system installed 10 spray bars in the inlet plenum for ice crystal generation using 222 spray nozzles. As an altitude test chamber, the PSL is capable of simulating icing events at altitude in a groundtest facility. The system was designed to operate at altitudes from 4,000 to 40,000 ft at Mach numbers up to 0.8M and inlet total temperatures from -60 to +15 degF. This paper and presentation will be part of a series of presentations on PSL Icing and will cover the development of the icing capability through design, developmental testing, installation, initial calibration, and validation engine testing. Information will be presented on the design criteria and process, spray bar developmental testing at Cox and Co., system capabilities, and initial calibration and engine validation test. The PSL icing system was designed to provide NASA and the icing community with a facility that could be used for research studies of engine icing by duplicating in-flight events in a controlled ground-test facility. With the system and the altitude chamber we can produce flight conditions and cloud environments to simulate those encountered in flight. The icing system can be controlled to set various cloud uniformities, droplet median volumetric diameter (MVD), and icing water content (IWC) through a wide variety of conditions. The PSL chamber can set altitudes, Mach numbers, and temperatures of interest to the icing community and also has the instrumentation capability of measuring engine performance during icing testing. PSL last year completed the calibration and initial engine validation of the facility utilizing a Honeywell ALF502-R5 engine and has duplicated in-flight roll back conditions experienced during flight testing. This paper will summarize the modifications and buildup of the facility to accomplish these tests.

  16. A telescience monitoring and control concept for a CELSS plant growth chamber

    NASA Technical Reports Server (NTRS)

    Rasmussen, Daryl N.; Mian, Arshad

    1989-01-01

    Consideration is given to the use of telescience to monitor and control a Space Station CELSS plant growth chamber (PGC). The proposed telescience control system contains controllers for PGC subsystems, a local master controller, and remote controllers. The benefits of telescience are discussed and the functional requirements of the PGC are outlined. A typical monitoring and control scenario is described. It is suggested that the proposed concept would provide remote access to a ground-based CELSS research facility, Space Station plant growth facilities, lunar-based CELSS facilities, and manned interplanetary spacecraft.

  17. Influence of high rotational speeds on heat transfer and oil film thickness in aero-engine bearing chambers

    Microsoft Academic Search

    S. Wittig; A. Glahn; J. Himmelsbach

    1994-01-01

    Increasing the thermal loading of bearing chambers in modern aero-engines requires advanced techniques for the determination of heat transfer characteristics. In the present study, film thickness and heat transfer measurements have been carried out for the complex two-phase oil\\/air flow in bearing chambers. In order to ensure real engine conditions, a new test facility has been built up, designed for

  18. LABORATORY ANIMAL FACILITIES STANDARD OPERATING PROCEDURE

    E-print Network

    Krovi, Venkat

    Faculty, students, and technicians who work with live animals in their labs or testing rooms. 2.0 Procedure 2.1 All equipment, transfer boxes, and holding/testing chambers used for animal research1.C.7 LABORATORY ANIMAL FACILITIES STANDARD OPERATING PROCEDURE FOR SANITATION OF RESEARCH

  19. Performance evaluation of multi sampling ionization chamber for heavy ion beams by comparison with GEANT4 simulation

    NASA Astrophysics Data System (ADS)

    Kanke, Yuki; Himac H093 Collaboration

    2014-09-01

    In high-energy heavy-ion accelerator facilities, multi sampling ionization chambers are often used for the identification of the atomic number Z by detecting the energy deposit in it. In the study at GSI, the picture of the escape of secondary electrons, ? rays, from the ionization chamber explains the experimental data of pulse-height resolution. If this picture is correct, the pulse-height resolution should depend on the effective area of the ionization chamber. The experiment have been performed at NIRS-HIMAC. The pulse-height resolutions of two ionization chambers with different effective area were compared by using a 400-MeV/u Ni beam and their fragments. The difference in the pulse-height resolutions was observed. By comparison with the GEANT4 simulation including the ?-rays emission, the performance of the ionization chamber have been evaluated.

  20. Blogs Are Echo Chambers: Blogs Are Echo Chambers Eric Gilbert, Tony Bergstrom and Karrie Karahalios

    E-print Network

    Karahalios, Karrie G.

    Blogs Are Echo Chambers: Blogs Are Echo Chambers Eric Gilbert, Tony Bergstrom and Karrie Karahalios decade, blogs have exploded in number, popularity and scope. However, many commentators and researchers speculate that blogs isolate readers in echo chambers, cutting them off from dissenting opin- ions. Our

  1. OPSys: optical payload systems facility for testing space coronagraphs

    Microsoft Academic Search

    S. Fineschi; G. Crescenzio; G. Massone; G. Capobianco; L. Zangrilli; E. Antonucci; F. Anselmi

    2011-01-01

    The Turin Astronomical Observatory, Italy, has implemented in ALTEC, Turin, a new Optical Payload Systems (OPSys) facility for testing of contamination sensitive optical space flight instrumentation. The facility is specially tailored for tests on solar instruments like coronagraphs. OPSys comprises an ISO 7 clean room for instrument assembly and a relatively large (4.4 m3) optical test and calibration vacuum chamber:

  2. Variable Temperature Total AC Loss and Stability Characterization Facility

    Microsoft Academic Search

    Sastry Pamidi; Doan Nguyen; Guomin Zhang; David Knoll; Ulf Trociewitz; Justin Schwartz

    2007-01-01

    The design of a versatile ac loss and stability characterization facility for high temperature superconducting materials suitable for variable temperature measurements is described. A non-metallic vessel inside a transverse field double-helix magnet acts as the measurement chamber. A cryocooler cools the samples to a target measurement temperature between 35 and 80 K. The facility is suitable for measurements on samples

  3. Zero Gravity Facility for space vehicle fluid systems research.

    NASA Technical Reports Server (NTRS)

    Petrash, D. A.; Corpas, E. L.

    1973-01-01

    Review of the major features and characteristics of the 5- to 10-second Zero Gravity Facility of the NASA Lewis Research Center. The facility consists primarily of a vertical (155 m) vacuum chamber wherein a variety of free-fall (weightless) experiments can be performed.-

  4. Chamber construction for internal combustion engine

    Microsoft Academic Search

    G. F. Jr. Leydorf; M. A. Pulick

    1987-01-01

    A method is described of assembling an internal combustion engine, comprising: (a) defining a three piece construction to define the combustion chambers, camshaft case, water jacket, and crankshaft case of the internal combustion engine. The three pieces consist of a cast metal monoblock defining combustion chambers aligned along a central plane. The monoblock contains wear resistant surfaces comprising cylinder bores,

  5. Aspect Ratio of Thermal Diffusion Chambers

    Microsoft Academic Search

    E. M. Tomlinson; N. Fukuta

    1979-01-01

    The supersaturation distribution inside thermal diffusion chambers of cylindrical symmetry with a linear vertical temperature gradient on the wall was computed with various aspect ratios using the vapor pressure field. The results were compared with previous works. It was shown that the effect of the wall on the supersaturation inside the chamber is much reduced when a linear temperature gradient

  6. Assessing uniformity in soil plant atmosphere chambers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growth chambers provide precisely controlled environments in which to grow plants and evaluate the effects of one or more controllable parameters on plant responses. Because of this precise control, it is arguable that less plant replication is required in growth chamber versus field studies. Howe...

  7. Neutron-chamber detectors and applications

    NASA Astrophysics Data System (ADS)

    Fehlau, Paul E.; Atwater, Henry F.; Coop, Kenneth L.

    1990-12-01

    Detector applications in nuclear safeguards and waste management have included measuring neutrons from fission and (?, n) reactions with well-moderated neutron proportional counters, often embedded in a slab of polyethylene. Other less-moderated geometries are useful for detecting both bare and moderated fission-source neutrons with good efficiency. The neutron chamber is an undermoderated detector design comprising a large, hollow, polyethylene-walled chamber containing one or more proportional counters. Neutron-chamber detectors are relatively inexpensive, can have large apertures, usually through a thin chamber wall, and offer very good detection efficiency per dollar. For 10% of the cost, a neutron-chamber detector may give one-half the total detection efficiency of a slab detector for detecting neutrons from a distant, bare source. A nuclear-safeguards pedestrian monitor detects concealed plutonium using two such chamber detectors to form a walk-through portal. Neutron-chamber detectors have also been used for monitoring vehicles and for assaying large crates of transuranic waste. Our Monte Carlo calculations for a new application (monitoring low-density waste for concealed plutonium) illustrate the advantages of the hollow-chamber design for detecting moderated fission sources.

  8. Promoting "Minds-on" Chamber Music Rehearsals

    ERIC Educational Resources Information Center

    Berg, Margaret H.

    2008-01-01

    Chamber music provides myriad opportunities to develop students' ability to think like professional musicians while engaged in the authentic task of working closely with and learning from peers. However, the potential for musical growth inherent in chamber music participation is often unrealized due to either a lack of teacher guidance and support…

  9. Dual-purpose chamber-cooling system

    NASA Technical Reports Server (NTRS)

    Fraze, R. E.

    1968-01-01

    Inexpensive, portable system was designed for cooling small environmental test chambers with a temperature-controlled gas stream evaporated from a cryogenic liquid. The system reduces the temperature of a chamber to any desired point in a fraction of the time required by previous systems.

  10. Polarimetric field characterization in reverberating chambers

    Microsoft Academic Search

    Paolo Corona; Giuseppe Ferrara; Maurizio Migliaccio

    2004-01-01

    Proper use of reverberating chambers calls for a complete characterization of its electromagnetic field. In this paper, we provide a theoretical background for an unambiguous port-to-port polarimetric field characterization. This allows us to provide some experimental test in support of the popular and key assumption of total depolarization in a well-operated reverberating chamber.

  11. Results from the MAC Vertex chamber

    SciTech Connect

    Nelson, H.N.

    1987-05-01

    The design, construction, and performance characteristics of a high precision gaseous drift chamber made of thin walled proportional tubes are described. The device achieved an average spatial resolution of 45 ..mu..m in use for physics analysis with the MAC detector. The B-lifetime result obtained with this chamber is discussed.

  12. The NASA Ames Closed Environmental Research Chamber: Present Status

    NASA Technical Reports Server (NTRS)

    Gross, Anthony R.; Korsmeyer, David J.; Harper, Lynn D.; Force, Edwin L.

    1994-01-01

    The Closed Environmental Research Chamber (CERC) at the NASA Ames Research Center was created to investigate both components and complete systems for life support of advanced space exploration missions. This facility includes a Main Chamber, an Airlock, a Sample Transfer Lock, a Vacuum System, an Air Recompression System, a dedicated control room and a pit area for housing supporting and environmental control systems. The Main Chamber provides 310 sq ft of internal working/living space on two levels. It is planned that the CERC will be a human-rated facility for habitation simulation under mass balance closure conditions. The internal pressure will be variable over the range of 14.7 psia to 5 psia with accompanying capability for variation in atmosphere composition to maintain the oxygen partial pressure at 160 mm Hg. The CERC will be provided with a core set of primary life support subsystems for temperature and humidity control, C02 removal and trace contaminant control. Interfacing with external life support technology test bds with be provided, along with connection to centralized, microprocessor-based data acquisition and control systems. This paper will discuss the current status of the CERC facility and show how it is being used to address the advanced technology requirements necessary to implement an integrated working and living environment for a planetary habitat. In particular, it will be shown how the CERC, along with a human-powered centrifuge, a planetary terrain simulator and advanced displays and a virtual reality capability will work together to develop and demonstration applicable technologies for future planetary habitats. Artificial intelligence and expert system programming techniques will be used extensively to provide an automated environment for a 4-person crew. There will be several robotic mechanisms performing exploration tasks external to the habitat that will be controlled through the virtual environment to provide representative workloads for the crew. Finally, there will be a discussion of how effective are innovative new multidisciplinary test facilities to the investigation of the wide range of human and machine problems inherent in exploration missions.

  13. Signal propagation in long wire chambers

    NASA Astrophysics Data System (ADS)

    Bock, P.; Engelfried, J.; Friedrich, T.; Heintze, J.; Lennert, P.; Russ, M.; Zimmer, M.

    2012-09-01

    The propagation of signals in long proportional counters or multi-wire tracking chambers is simulated, using numerical solutions of the multi-wire telegraph equations. The results are compared to experimental data, recorded with a proportional counter and a multi-wire test chamber. The signal shape, the charge division ratio and, in the case of the drift chamber, also the cross talk between the wires, are well reproduced. Similar shapes for signals and their cross talk can be obtained with a properly chosen electrical termination. It is shown how data from a multi-wire chamber can then be corrected for cross talk. The effects limiting the precision of position measurements along the wires with the charge division method are discussed. The simulation was applied to the reconstruction of tracks measured with the OPAL JET chamber.

  14. Wet drift chambers for precise luminosity

    NASA Astrophysics Data System (ADS)

    Anderson, B. E.; Kennedy, B. W.; Ahmet, K.; Attree, D. J.; Barraclough, G. A.; Cresswell, M. J.; Hayes, D. A.; Miller, D. J.; Selby, C.; Sherwood, P.

    1994-09-01

    A set of high-precision compact drift chambers has been a vital component of the OPAL luminosity monitor since the start of data-taking at LEP. They were augmented in 1992 by the addition of Small Angle Reference Chambers with a very similar design to the original chamber. The performance of the chambers is reviewed, highlighting both the importance of using polyalkylene glycol (Breox) to maintain a uniform and parallel electric field and the construction techniques used to sustain the required field strength. We describe some of the operating problems, with their solutions, and show how the chambers have been used in achieving a systematic error of 0.41% on the luminosity measurement.

  15. Combustion chamber for an internal-combustion engine

    Microsoft Academic Search

    Ishida

    1987-01-01

    A combustion chamber for an internal-combustion engine is described comprising: a main combustion chamber defined by a first recess in the top surface of the crown of a piston; an auxiliary combustion chamber defined by a second recess in the top surface of the crown of the piston beside the main combustion chamber, the volume of the auxiliary combustion chamber

  16. TRIDENT high-energy-density facility experimental capabilities and diagnostics

    SciTech Connect

    Batha, S. H.; Aragonez, R.; Archuleta, F. L.; Archuleta, T. N.; Benage, J. F.; Cobble, J. A.; Cowan, J. S.; Fatherley, V. E.; Flippo, K. A.; Gautier, D. C.; Gonzales, R. P.; Greenfield, S. R.; Hegelich, B. M.; Hurry, T. R.; Johnson, R. P.; Kline, J. L.; Letzring, S. A.; Loomis, E. N.; Lopez, F. E.; Luo, S. N. [Los Alamos National Laboratory, P.O. Box 1663, MS E526, Los Alamos, New Mexico 87545 (United States)] (and others)

    2008-10-15

    The newly upgraded TRIDENT high-energy-density (HED) facility provides high-energy short-pulse laser-matter interactions with powers in excess of 200 TW and energies greater than 120 J. In addition, TRIDENT retains two long-pulse (nanoseconds to microseconds) beams that are available for simultaneous use in either the same experiment or a separate one. The facility's flexibility is enhanced by the presence of two separate target chambers with a third undergoing commissioning. This capability allows the experimental configuration to be optimized by choosing the chamber with the most advantageous geometry and features. The TRIDENT facility also provides a wide range of standard instruments including optical, x-ray, and particle diagnostics. In addition, one chamber has a 10 in. manipulator allowing OMEGA and National Ignition Facility (NIF) diagnostics to be prototyped and calibrated.

  17. Studies of Helium Based Gas Mixtures Using a Small Cell Drift Chamber

    SciTech Connect

    Heise, Jaret; /British Columbia U.

    2006-07-07

    An international collaboration is currently working on the construction and design of an asymmetric B Factory at the Stanford Linear Accelerator Center that will be ready to collect data in 1999. The main physics motivation for such a facility is to test the description and mechanism of CP violation in the Standard Model of particle physics and provide insight into the question of why more matter than antimatter is observed in the universe today. In particular, this experiment will measure CP violation in the decay of B mesons. In the early stages of this effort, the Canadian contingent proposed to build the central tracking chamber for the BaBar detector. Presently, a prototype drift chamber is in operation and studies are being performed to test some of the unique features of drift chamber design dictated by the conditions of the experiment. Using cosmic muons, it is possible to study tracking and pattern recognition in the prototype chamber, and therefore calculate the efficiency and spatial resolution of the prototype chamber cells. These performance features will be used to test whether or not the helium-based gas mixtures proposed for the BaBar drift chamber are a viable alternative to the more traditional argon-based gases.

  18. Characterizing the acoustic properties of the Jet Lab at the National Center for Physical Acoustics

    NASA Astrophysics Data System (ADS)

    Lieblong, Joshua Anderson

    Aerodynamic noise has been a problem since the first use of the jet engine for military aircraft in World War II. For further uses of the jet engine to be possible, problems due to jet noise must be researched and addressed. Anechoic chambers were proposed as a testing facility for research in aerodynamic noise because of their supposed free-field characteristics. The international standard ISO 3745-1977 was introduced to determine whether the facilities could be considered anechoic, semi-anechoic, or neither. An experiment was designed to determine at what frequencies the National Center for Physical Acoustics' Jet Lab Facility is non-anechoic, semi-anechoic, or anechoic. To comply with the guidelines of ISO 3745- 1977, three sources were designed and tested at frequencies from 25 Hz to 16000 Hz. The voltages were acquired at each frequency to calculate the sound pressure level and determine if the calculated values are within the allowed tolerance of the inverse square law.

  19. Construction of a fast ionization chamber for high-rate particle identification

    NASA Astrophysics Data System (ADS)

    Chae, K. Y.; Ahn, S.; Bardayan, D. W.; Chipps, K. A.; Manning, B.; Pain, S. D.; Peters, W. A.; Schmitt, K. T.; Smith, M. S.; Strauss, S. Y.

    2014-07-01

    A new gas-filled ionization chamber for high count rate particle identification has been constructed and commissioned at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL). To enhance the response time of the ionization chamber, a design utilizing a tilted entrance window and tilted electrodes was adopted, which is modified from an original design by Kimura et al. [1]. A maximum counting rate of ~700,000 particles per second has been achieved. The detector has been used for several radioactive beam measurements performed at the HRIBF.

  20. Calibration of the borated ion chamber at NIST reactor thermal column.

    PubMed

    Wang, Z; Hertel, N E; Lennox, A

    2007-01-01

    In boron neutron capture therapy and boron neutron capture enhanced fast neutron therapy, the absorbed dose of tissue due to the boron neutron capture reaction is difficult to measure directly. This dose can be computed from the measured thermal neutron fluence rate and the (10)B concentration at the site of interest. A borated tissue-equivalent (TE) ion chamber can be used to directly measure the boron dose in a phantom under irradiation by a neutron beam. Fermilab has two Exradin 0.5 cm(3) Spokas thimble TE ion chambers, one loaded with boron, available for such measurements. At the Fermilab Neutron Therapy Facility, these ion chambers are generally used with air as the filling gas. Since alpha particles and lithium ions from the (10)B(n,alpha)(7)Li reactions have very short ranges in air, the Bragg-Gray principle may not be satisfied for the borated TE ion chamber. A calibration method is described in this paper for the determination of boron capture dose using paired ion chambers. The two TE ion chambers were calibrated in the thermal column of the National Institute of Standards and Technology (NIST) research reactor. The borated TE ion chamber is loaded with 1,000 ppm of natural boron (184 ppm of (10)B). The NIST thermal column has a cadmium ratio of greater than 400 as determined by gold activation. The thermal neutron fluence rate during the calibration was determined using a NIST fission chamber to an accuracy of 5.1%. The chambers were calibrated at two different thermal neutron fluence rates: 5.11 x 10(6) and 4.46 x 10(7)n cm(-2) s(-1). The non-borated ion chamber reading was used to subtract collected charge not due to boron neutron capture reactions. An optically thick lithium slab was used to attenuate the thermal neutrons from the neutron beam port so the responses of the chambers could be corrected for fast neutrons and gamma rays in the beam. The calibration factor of the borated ion chamber was determined to be 1.83 x 10(9) +/- 5.5% (+/- 1sigma) n cm(-2) per nC at standard temperature and pressure condition. PMID:17525059

  1. A study of radar cross section measurement techniques

    Microsoft Academic Search

    Malcolm W. McDonald

    1986-01-01

    Past, present, and proposed future technologies for the measurement of radar cross section were studied. The purpose was to determine which method(s) could most advantageously be implemented in the large microwave anechoic chamber facility which is operated at the antenna test range site. The progression toward performing radar cross section measurements of space vehicles with which the Orbital Maneuvering Vehicle

  2. Compressive sensing based beamforming and its application in aeroacoustic experiment

    E-print Network

    Huang, Xun

    . Aeroacoustic experiments performed in wind tunnel and anechoic chamber jet facility usually contain strong background noise at broadband frequencies. These issues from the specific application impose challenges shows that the CSB-I algorithm is quite sensitive to the sensing noise. The CSB-II algorithm

  3. Compressive sensing beamforming based on covariance for acoustic imaging with noisy

    E-print Network

    Huang, Xun

    and anechoic chamber jet facility usually contain strong background noise at broad- band frequencies measurements. The simulation results clearly show that the proposed CSB-II method is robust to sensing noise problem. It was verified using both simulated data with various signal-to-noise ratios (SNR) and measured

  4. Adaptive beamforming for array signal processing in aeroacoustic measurements

    E-print Network

    Huang, Xun

    , and sharp trailing edges, have recently been tested in wind tunnels and anechoic chambers to investigate, a test facility has to be modified specifically to reduce background noise and to mitigate wall effect of the background noise. More design details can be found in Refs. 4, 13, and 14. On the other

  5. Precision and accuracy of jet noise measurements

    Microsoft Academic Search

    C. T. Savell

    1977-01-01

    Statistical methods of analyzing the accuracy and precision of acoustic measurements are developed and demonstrated in evaluating glossial, anechoic chamber jet noise facility. Errors introduced by: contamination from a nonjet noise sources; inaccuracies in aerodynamic measurement; air attenuation inaccuracies from an inadequate attenuation model, ambient gradients and inaccurate meteorological measurements; deviation from a freefield arena; and contamination from electronic noise

  6. Development of a EUV Test Facility at the Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    West, Edward; Pavelitz, Steve; Kobayashi, Ken; Robinson, Brian; Cirtain, Johnathan; Gaskin, Jessica; Winebarger, Amy

    2011-01-01

    This paper will describe a new EUV test facility that is being developed at the Marshall Space Flight Center (MSFC) to test EUV telescopes. Two flight programs, HiC - high resolution coronal imager (sounding rocket) and SUVI - Solar Ultraviolet Imager (GOES-R), set the requirements for this new facility. This paper will discuss those requirements, the EUV source characteristics, the wavelength resolution that is expected and the vacuum chambers (Stray Light Facility, Xray Calibration Facility and the EUV test chamber) where this facility will be used.

  7. Temperature dependent BRDF facility

    NASA Astrophysics Data System (ADS)

    Airola, Marc B.; Brown, Andrea M.; Hahn, Daniel V.; Thomas, Michael E.; Congdon, Elizabeth A.; Mehoke, Douglas S.

    2014-09-01

    Applications involving space based instrumentation and aerodynamically heated surfaces often require knowledge of the bi-directional reflectance distribution function (BRDF) of an exposed surface at high temperature. Addressing this need, the Johns Hopkins University Applied Physics Laboratory (JHU/APL) developed a BRDF facility that features a multiple-port vacuum chamber, multiple laser sources covering the spectral range from the longwave infrared to the ultraviolet, imaging pyrometry and laser heated samples. Laser heating eliminates stray light that would otherwise be seen from a furnace and requires minimal sample support structure, allowing low thermal conduction loss to be obtained, which is especially important at high temperatures. The goal is to measure the BRDF of ceramic-coated surfaces at temperatures in excess of 1000°C in a low background environment. Most ceramic samples are near blackbody in the longwave infrared, thus pyrometry using a LWIR camera can be very effective and accurate.

  8. Vapor wall deposition in Teflon chambers

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Schwantes, R. H.; McVay, R. C.; Lignell, H.; Coggon, M. M.; Flagan, R. C.; Seinfeld, J. H.

    2015-04-01

    Teflon chambers are ubiquitous in studies of atmospheric chemistry. Secondary organic aerosol (SOA) formation can be underestimated, owing to deposition of SOA-forming vapors to the chamber wall. We present here an experimental protocol and a model framework to constrain the vapor-wall interactions in Teflon chambers. We measured the wall deposition rates of 25 oxidized organic compounds generated from the photooxidation of isoprene, toluene, ?-pinene, and dodecane in two chambers that had been extensively used and in two new unused chambers. We found that the extent of prior use of the chamber did not significantly affect the sorption behavior of the Teflon films. Among the 25 compounds studied, the maximum wall deposition rate is exhibited by the most highly oxygenated and least volatile compounds. By optimizing the model output to the observed vapor decay profiles, we identified that the dominant parameter governing the extent of wall deposition of a compound is its wall accommodation coefficient (?wi), which can be correlated through its volatility with the number of carbons and oxygens in the molecule. By doing so, the wall-induced deposition rate of intermediate/semi-volatile organic vapors can be reasonably predicted based on their molecular constituency. The extent to which vapor wall deposition impacts measured SOA yields depends on the competition between uptake of organic vapors by suspended particles and the chamber wall. The timescale associated with vapor wall deposition can vary from minutes to hours depending on the value of ?w,i. For volatile and intermediate volatility organic compounds (small ?w,i), gas-particle partitioning will dominate wall deposition for typical particle number concentrations in chamber experiments. For compounds characterized by relatively large ?w,i, vapor transport to particles is suppressed by competition with the chamber wall even with perfect particle accommodation.

  9. Vapor wall deposition in Teflon chambers

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Schwantes, R. H.; McVay, R. C.; Lignell, H.; Coggon, M. M.; Flagan, R. C.; Seinfeld, J. H.

    2014-10-01

    Teflon chambers are ubiquitous in studies of atmospheric chemistry. Secondary organic aerosol (SOA) formation can be substantially underestimated owing to deposition of SOA-forming compounds to chamber walls. We present here an experimental protocol to constrain the nature of wall deposition of organic vapors in Teflon chambers. We measured the wall deposition rates of 25 oxidized organic compounds generated from the photooxidation of isoprene, toluene, ?-pinene, and dodecane in two chambers that had been extensively used and in two new unused chambers. We found that the extent of prior use of the chamber did not significantly affect the sorption behavior of the Teflon films. The dominant parameter governing the extent of wall deposition of a compound is its wall accommodation coefficient (?w,i), which can be correlated through its volatility (Ci*) with the number of carbons (nC) and oxygens (nO) in the molecule. Among the 25 compounds studied, the maximum wall deposition rate is approached by the most highly oxygenated and least volatile compounds. The extent to which vapor wall deposition impacts measured SOA yields depends on the competition between uptake of organic vapors by suspended particles and chamber walls. Gas-particle equilibrium partitioning is established relatively rapidly in the presence of perfect accommodation of organic vapors onto particles or when a sufficiently large concentration of suspended particles is present. The timescale associated with vapor wall deposition can vary from minutes to hours depending on the value of ?w,i. For volatile and intermediate volatility organic compounds (small ?w,i), gas-particle partitioning will be dominant for typical particle number concentrations in chamber experiments. For large ?w,i, vapor transport to particles is suppressed by competition with the chamber walls even with perfect particle accommodation.

  10. Characterization and testing of a new environmental chamber designed for emission aging studies

    NASA Astrophysics Data System (ADS)

    Leskinen, A.; Yli-Pirilä, P.; Kuuspalo, K.; Sippula, O.; Jalava, P.; Hirvonen, M.-R.; Jokiniemi, J.; Virtanen, A.; Komppula, M.; Lehtinen, K. E. J.

    2014-06-01

    A 29 m3 Teflon chamber, designed for aging studies of combustion aerosols, at the University of Eastern Finland is described and characterized. The chamber belongs to a research facility, called Ilmari, where small-scale combustion devices, a dynamometer for vehicle exhaust studies, dilution systems, the chamber, as well as cell and animal exposure devices are side by side under the same roof. The small surface-to-volume ratio of the chamber enables reasonably long experiment times, with particle wall loss rate constants of 0.088, 0.080, 0.045, and 0.040 h-1 for polydisperse, 50, 100, and 200 nm monodisperse aerosols, respectively. The NO2 photolysis rate can be adjusted from zero to 0.62 min-1. The irradiance spectrum is centered at 365 nm and the maximum irradiance, produced by 160 blacklight lamps, is 29.7 W m-2, which corresponds to the UV irradiance in Central Finland at noon on a sunny day in the midsummer. The temperature inside the chamber is uniform and can be kept at 25 ± 1 °C when half of the blacklights are on. The chamber is kept in an overpressure with a moving top frame, which prevents sample dilution and contamination from entering the chamber during an experiment. The functionality of the chamber was tested with oxidation experiments of toluene, resulting in secondary organic aerosol (SOA) yields of 33-44%, depending on the initial conditions, such as the NOx concentration. The highest gaseous oxidation product yields of 14.4-19.5% were detected with ions corresponding to 2-butenedial (m/z 73.029) and 4-oxo-2-pentenal (m/z 99.044). Overall, reasonable yields of SOA and gaseous reaction products, comparable to those obtained in other laboratories, were obtained.

  11. The emulsion chamber technology experiment

    NASA Technical Reports Server (NTRS)

    Gregory, John C.

    1992-01-01

    Photographic emulsion has the unique property of recording tracks of ionizing particles with a spatial precision of 1 micron, while also being capable of deployment over detector areas of square meters or 10's of square meters. Detectors are passive, their cost to fly in Space is a fraction of that of instruments of similar collecting. A major problem in their continued use has been the labor intensiveness of data retrieval by traditional microscope methods. Two factors changing the acceptability of emulsion technology in space are the astronomical costs of flying large electronic instruments such as ionization calorimeters in Space, and the power and low cost of computers, a small revolution in the laboratory microscope data-taking. Our group at UAH made measurements of the high energy composition and spectra of cosmic rays. The Marshall group has also specialized in space radiation dosimetry. Ionization calorimeters, using alternating layers of lead and photographic emulsion, to measure particle energies up to 10(exp 15) eV were developed. Ten balloon flights were performed with them. No such calorimeters have ever flown in orbit. In the ECT program, a small emulsion chamber was developed and will be flown on the Shuttle mission OAST-2 to resolve the principal technological questions concerning space exposures. These include assessments of: (1) pre-flight and orbital exposure to background radiation, including both self-shielding and secondary particle generation; the practical limit to exposure time in space can then be determined; (2) dynamics of stack to optimize design for launch and weightlessness; and (3) thermal and vacuum constraints on emulsion performance. All these effects are cumulative and affect our ability to perform scientific measurements but cannot be adequately predicted by available methods.

  12. The Japanese Radon and Thoron Reference Chambers

    SciTech Connect

    Tokonami, Shinji; Ishikawa, Tetsuo; Sorimachi, Atsuyuki; Takahashi, Hiroyuki; Miyahara, Nobuyuki [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)

    2008-08-07

    Passive detectors used for large-scale and long-term surveys are generally calibrated in a well-controlled environment such as a radon chamber. It has been also pointed out that some of them are sensitive to thoron. Thus it is necessary to check the thoron contribution to the detector response with the proposed or similar test before practical use. The NIRS accommodates radon/aerosol and thoron chambers for quality assurance and quality control of radon measurements. Thus both chambers work so well that they can supply us with the calibration technique and consequently, a good level of knowledge of the radon and thoron issue.

  13. Sample chambers with mother-daughter mode

    SciTech Connect

    Wilk, P.A.; Gregorich, K.E.; Hoffman, D.C.

    2001-07-12

    A set of eight stand-alone sample chambers with a common interface were constructed at LBNL for improved detection of alpha and fission decay chains over currently used designs. The stainless steel chambers (see Figure 1 for a schematic and Figure 2 for a photograph of a completed chamber) were constructed to allow for low background detection of a daughter event by removal of the sample following the detection of a parent event. This mother-daughter mode of operation has been utilized successfully with our Merry-go-Round (MG) detection system [Gregorich 1994].

  14. 21 CFR 880.5450 - Patient care reverse isolation chamber.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Patient care reverse isolation chamber. 880.5450 Section...Devices § 880.5450 Patient care reverse isolation chamber. (a) Identification. A patient care reverse isolation chamber is a...

  15. 21 CFR 880.5450 - Patient care reverse isolation chamber.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Patient care reverse isolation chamber. 880.5450 Section...Devices § 880.5450 Patient care reverse isolation chamber. (a) Identification. A patient care reverse isolation chamber is a...

  16. Nuclear Facilities

    NSDL National Science Digital Library

    Christopher Griffith

    In order to produce nuclear weapons, each country must have facilities to produce and refine the nuclear materials, conduct research on weapon design, and store the completed weapons. The interactives in this collection allow you to explore the nuclear facilities of the nuclear powers (both declared and undeclared).

  17. Automated Transmission Loss Measurement in the Structural Acoustic Loads and Transmission Facility at NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Klos, J.; Brown, S. A.

    2002-01-01

    A technique to measure the radiated acoustic intensity and transmission loss of panels is documented in this paper. This facility has been upgraded to include a test fixture that scans the acoustic intensity radiated from a panel on the anechoic receiving room side of the transmission loss window. The acoustic intensity incident on the panel from the reverberant side of the transmission loss window is estimated from measurements made using six stationary microphones in the reverberant source room. From the measured incident and radiated intensity, the sound power transmission loss is calculated. The setup of the facility and data acquisition system are documented. A transmission loss estimate of a typical panel is shown. The measurement-to-measurement and setup-to-setup repeatability of the transmission loss estimate are assessed. Conclusions are drawn about the ability to measure changes in transmission loss due to changes in panel construction.

  18. Multilayer coating facility for the HEFT hard X-ray telescope Carsten P. Jensena

    E-print Network

    . 2. COATING FACILITY The facility is a 0.8 m3 vacuum-chamber (bell-jar) with two planar DC magnetronMultilayer coating facility for the HEFT hard X-ray telescope Carsten P. Jensena , Finn E) for the production coating of depth graded multilayers on the thermally slumped glass segments which form the basis

  19. Accelerated Solar-UV Test Chamber

    NASA Technical Reports Server (NTRS)

    Gupta, A.; Laue, E. G.

    1984-01-01

    Medium-pressure mercury-vapor lamps provide high ratio of ultraviolet to total power. Chamber for evaluating solar-ultraviolet (UV) radiation damage permits accelerated testing without overheating test specimens.

  20. Rocket Combustion Chambers Resist Thermal Fatigue

    NASA Technical Reports Server (NTRS)

    Kazaroff, John M.; Jankovsky, Robert S.; Pavli, Albert J.

    1995-01-01

    Improved design concept developed for combustion chambers for rocket engines, described in three reports. Provides compliance allowing unrestrained thermal expansion in circumferential direction. Compliance lengthens life of rocket engine by reducing amount of thermal deformation caused by repeated firings.

  1. Lunar Heat Flow Simulation and Testing Chamber

    NASA Astrophysics Data System (ADS)

    Smrekar, S. E.; Mungas, G.; Peters, G.; Hudson, T. L.; Morgan, P.

    2009-03-01

    Heat flow is a key indicator of planetary thermal and chemical evolution. We have constructed a vacuum chamber to provide a testbed for evaluating heat flow instrumentation and measurement issues and calibration techniques prior to flight.

  2. Lunar Heat Flow Simulation and Testing Chamber

    Microsoft Academic Search

    S. E. Smrekar; G. Mungas; G. Peters; T. L. Hudson; P. Morgan

    2009-01-01

    Heat flow is a key indicator of planetary thermal and chemical evolution. We have constructed a vacuum chamber to provide a testbed for evaluating heat flow instrumentation and measurement issues and calibration techniques prior to flight.

  3. Three dimensional thrust chamber life prediction

    NASA Technical Reports Server (NTRS)

    Armstrong, W. H.; Brogren, E. W.

    1976-01-01

    A study was performed to analytically determine the cyclic thermomechanical behavior and fatigue life of three configurations of a Plug Nozzle Thrust Chamber. This thrust chamber is a test model which represents the current trend in nozzle design calling for high performance coupled with weight and volume limitations as well as extended life for reusability. The study involved the use of different materials and material combinations to evaluate their application to the problem of low-cycle fatigue in the thrust chamber. The thermal and structural analyses were carried out on a three-dimensional basis. Results are presented which show plots of continuous temperature histories and temperature distributions at selected times during the operating cycle of the thrust chamber. Computed structural data show critical regions for low-cycle fatigue and the histories of strain within the regions for each operation cycle.

  4. Developing Cloud Chambers with High School Students

    NASA Astrophysics Data System (ADS)

    Ishizuka, Ryo; Tan, Nobuaki; Sato, Shoma; Zeze, Syoji

    The result and outcome of the cloud chamber project, which aims to develop a cloud chamber useful for science education is reported in detail. A project includes both three high school students and a teacher as a part of Super Science High School (SSH) program in our school. We develop a dry-ice-free cloud chamber using salt and ice (or snow). Technical details of the chamber are described. We also argue how the project have affected student's cognition, motivation, academic skills and behavior. The research project has taken steps of professional researchers, i.e., in planning research, applying fund, writing a paper and giving a talk in conferences. From interviews with students, we have learnt that such style of scientific activity is very effective in promoting student's motivation for learning science.

  5. Engine Knock and Combustion Chamber Form

    NASA Technical Reports Server (NTRS)

    Zinner, Karl

    1939-01-01

    The present report is confined to the effect of the combustion chamber shape on engine knock from three angles, namely: 1) The uniformity of flame-front movement as affected by chamber design and position of the spark plug; 2) The speed of advance of the flame as affected by turbulence and vibrations; 3) The reaction processes in the residual charge as affected by the walls.

  6. Vacuum chamber thermal protection for the APS

    Microsoft Academic Search

    S. L. Kramer; E. A. Crosbie; S. Kim; R. Wehrle; M. Yoon

    1989-01-01

    The authors summarize the results of a task group that studied the vacuum-chamber thermal protection problem for the Advanced Photon Source (APS). It is pointed out that the high-power-density photon beams in the proposed next generation of synchrotron light sources introduce new risks to the integrity of the ring vacuum chambers. In these machines, power densities are such that vacuum

  7. Tracking with wire chambers at the SSC

    SciTech Connect

    Hanson, G.G.; Gundy, M.C.; Palounek, A.P.T.

    1989-07-01

    Limitations placed on wire chambers by radiation damage and rate requirements in the SSC environment are reviewed. Possible conceptual designs for wire chamber tacking systems that meet these requirements are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 13 refs., 11 fig., 1 tab.

  8. Development of large planar proportional chambers

    NASA Astrophysics Data System (ADS)

    Bozzo, M.; Buzzo, A.; Ferroni, S.; Gracco, V.; Santroni, A.; Kiesler, R.; Kirsebom, K.; Macri, M.; Mouellic, B.

    1980-12-01

    We describe a set of large multiwire proportional chambers used in an experiment at the CERN Super Proton Synchrotron. The sensitive area is 2320 × 2320 mm 2, and four detecting planes, each with different orientation, are grouped together within the same mechanical frame. The number of wires for each module is 5000. Very uniform efficiency over the whole area is achieved by means of a simple mechanical construction. The chambers were operated for a long time without any damage under high particle flux.

  9. Cyclic fatigue analysis of rocket thrust chambers. Volume 1: OFHC copper chamber low cycle fatigue

    NASA Technical Reports Server (NTRS)

    Miller, R. W.

    1974-01-01

    A three-dimensional finite element elasto-plastic strain analysis was performed for the throat section of a regeneratively cooled rocket combustion chamber. The analysis employed the RETSCP finite element computer program. The analysis included thermal and pressure loads, and the effects of temperature dependent material properties, to determine the strain range corresponding to the chamber operating cycle. The analysis was performed for chamber configuration and operating conditions corresponding to a hydrogen-oxygen combustion chamber which was fatigue tested to failure. The computed strain range at typical chamber operating conditions was used in conjunction with oxygen-free, high-conductivity (OHFC) copper isothermal fatigue test data to predict chamber low-cycle fatigue life.

  10. Sandia National Laboratories' new high level acoustic test facility

    SciTech Connect

    Rogers, J. D.; Hendrick, D. M.

    1989-01-01

    A high intensity acoustic test facility has been designed and is under construction at Sandia National Laboratories in Albuquerque, NM. The chamber is designed to provide an acoustic environment of 154dB (re 20 {mu}Pa) overall sound pressure level over the bandwidth of 50 Hz to 10,000 Hz. The chamber has a volume of 16,000 cubic feet with interior dimensions of 21.6 ft {times} 24.6 ft {times} 30 ft. The construction of the chamber should be complete by the summer of 1990. This paper discusses the design goals and constraints of the facility. The construction characteristics are discussed in detail, as are the acoustic performance design characteristics. The authors hope that this work will help others in designing acoustic chambers. 12 refs., 6 figs.

  11. Chamber for Growing and Observing Fungi

    NASA Technical Reports Server (NTRS)

    Pierson, Duane L.; Molina, Thomas C.

    2005-01-01

    A chamber has been designed to enable growth and observation of microcolonies of fungi in isolation from the external environment. Unlike prior fungus-growing apparatuses, this chamber makes it possible to examine a fungus culture without disrupting it. Partly resembling a small picture frame, the chamber includes a metal plate having a rectangular through-thethickness opening with recesses for a top and a bottom cover glass, an inlet for air, and an inlet for water. The bottom cover glass is put in place and held there by clips, then a block of nutrient medium and a moisture pad are placed in the opening. The block is inoculated, then the top cover glass is put in place and held there by clips. Once growth is evident, the chamber can be sealed with tape. Little (if any) water evaporates past the edges of the cover glasses, and, hence there is little (if any) need to add water. A microscope can be used to observe the culture through either cover glass. Because the culture is sealed in the chamber, it is safe to examine the culture without risking contamination. The chamber can be sterilized and reused.

  12. TEMPERATURE GRADIENT CHAMBERS FOR RESEARCH ON GLOBAL ENVIRONMENT CHANGE. I. THERMAL ENVIRONMENT IN A LARGE CHAMBER

    Microsoft Academic Search

    M. OKADA; T. HAMASAKI; T. HAYASHI

    OKADA M. HAMASAKI T. and HAYASH! T. Temperature gradient chambers for research on global environment change. I. Thermal environment in a large chamber. BIOTRONICS 24, 85-97, 1995. Simple and low-cost temperature gradient chambers (TGC) have been developed to study the effects of temperature on field crops. Providing a continuous one-way air flow along the long axis of the TGC, the

  13. Radiometric calibration and mission simulation testing of sensor systems in the AEDC 7V and 10V chambers

    NASA Astrophysics Data System (ADS)

    Nicholson, R. A.; Mead, K. D.; Lowry, H. S.

    2006-05-01

    The Arnold Engineering Development Center (AEDC) has performed characterization and calibration of space-based, airborne, and interceptor sensor systems for over 35 years. The 7V and 10V Chambers provide a suite of IR and visible target systems that operate in a simulated space background (< 20K) and allow complete evaluation of sensor performance within a single test installation. Test facility upgrades are continuously pursued to keep pace with evolving sensor technologies. This paper describes the methodology used to perform calibration and characterization of sensor systems in the AEDC 7V and 10V test chambers. Complex target systems that provide the ability to evaluate system performance against representative mission scenarios are included in both test chambers. Representative results associated with the calibration and mission simulation capabilities are shown. The overall status of the 7V and 10V Chamber facilities is described, and plans to implement improved calibration capabilities are discussed. Results from analysis performed on data collected during checkout testing of source systems included in both sensor test chambers are presented. The results illustrate the ability of the 7V and 10V Chambers to facilitate complete characterization of sensor performance with a high degree of accuracy in a representative mission operating environment.

  14. Drift Velocity Calibration for the CLAS Drift Chamber System

    NASA Astrophysics Data System (ADS)

    Levy, Stephen L.; Gilfoyle, Gerard P.; Mestayer, Mac

    1996-05-01

    The University of Richmond Physics Department is responsible for projects being developed for the Continuous Electron Beam Accelerator Facility (CEBAF). We have constructed a prototype of the bow section of the Region 3 drift chambers of Hall B, called the nose cone prototype. Cosmic rays travel through the chamber and ionize atoms from its argon/ethane gas mixture. The displaced electrons drift toward sense wires due to the force exerted by an electric field. Using electronics to measure this drift time, we then compute the distance of closest approach of the track to the sense wire. These distances of closest approach allow us to reconstruct a track showing the trajectory of the cosmic ray. A major problem encountered with the prototype was that changing environmental conditions like the atmospheric pressure and other factors degraded its performance. The changes reduced the accuracy of the drift-time-to-drift-distance formula; leading to worse resolution. However, we have determined that accounting for the change in the maximum drift time can help us regain our accuracy. Data obtained from the drift time spectrum enables us to obtain an accurate value of this parameter. Using this updated value in a calibration file maintains the drift velocity function and the resolution.

  15. Focal Point Inside the Vacuum Chamber for Solar Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Researchers at the Marshall Space Flight Center (MSFC) have designed, fabricated, and tested the first solar thermal engine, a non-chemical rocket engine that produces lower thrust but has better thrust efficiency than a chemical combustion engine. MSFC turned to solar thermal propulsion in the early 1990s due to its simplicity, safety, low cost, and commonality with other propulsion systems. Solar thermal propulsion works by acquiring and redirecting solar energy to heat a propellant. The 20- by 24-ft heliostat mirror (not shown in this photograph) has dual-axis control that keeps a reflection of the sunlight on an 18-ft diameter concentrator mirror, which then focuses the sunlight to a 4-in focal point inside the vacuum chamber. The focal point has 10 kilowatts of intense solar power. This photograph is a close-up view of a 4-in focal point inside the vacuum chamber at the MSFC Solar Thermal Propulsion Test facility. As part of MSFC's Space Transportation Directorate, the Propulsion Research Center serves as a national resource for research of advanced, revolutionary propulsion technologies. The mission is to move the Nation's capabilities beyond the confines of conventional chemical propulsion into an era of aircraft-like access to Earth orbit, rapid travel throughout the solar system, and exploration of interstellar space.

  16. Team Huddle Before Lifting Phoenix into Test Chamber

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Spacecraft specialists huddle to discuss the critical lift of NASA's Phoenix Mars Lander into a thermal vacuum chamber.

    In December 2006, the spacecraft was in a cruise configuration prior to going into environmental testing at a Lockheed Martin Space Systems facility near Denver. At all stages of assembly and testing, the spacecraft is handled with extreme care and refinement.

    The Phoenix mission is led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory and development partnership with Lockheed Martin Space Systems. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen, and the Max Planck Institute in Germany. JPL is a division of the California Institute of Technology in Pasadena.

  17. Comments on settling chamber design for quiet, blowdown wind tunnels

    NASA Technical Reports Server (NTRS)

    Beckwith, I. E.

    1981-01-01

    Transfer of an existing continous circuit supersonic wind tunnel to Langley and its operation there as a blowdown tunnel is planned. Flow disturbance requirements in the supply section and methods for reducing the high level broad band acoustic disturbances present in typical blowdown tunnels are reviewed. Based on recent data and the analysis of two blowdown facilities at Langley, methods for reducing the total turbulence levels in the settling chamber, including both acoustic and vorticity modes, to less than one percent are recommended. The pertinent design details of the damping screens and honeycomb and the recommended minimum pressure drop across the porous components providing the required two orders of magnitude attenuation of acoustic noise levels are given. A suggestion for the support structure of these high pressure drop porous components is offered.

  18. Design characteristics of a heat pipe test chamber

    NASA Technical Reports Server (NTRS)

    Baker, Karl W.; Jang, J. Hoon; Yu, Juin S.

    1992-01-01

    LeRC has designed a heat pipe test facility which will be used to provide data for validating heat pipe computer codes. A heat pipe test chamber that uses helium gas for enhancing heat transfer was investigated. The conceptual design employs the technique of guarded heating and guarded cooling to facilitate accurate measurements of heat transfer rates to the evaporator and from the condenser. The design parameters are selected for a baseline heat pipe made of stainless steel with an inner diameter of 38.10 mm and a wall thickness of 1.016 mm. The heat pipe operates at a design temperature of 1000 K with an evaporator radial heat flux of 53 W/sq. cm.

  19. Numerical models on shallow magma chamber formation

    NASA Astrophysics Data System (ADS)

    Barnett, Zoe; Gudmundsson, Agust

    2013-04-01

    A magma chamber can be defined as a body within the crust that is either partially or totally molten which is injected with new magma from a deep-seated reservoir. A shallow magma chamber acts as a sink as it receives magma from the deeper reservoir, and as a source for volcanic eruptions. Most shallow magma chambers appear to develop from sills, and some, such as many mid-ocean ridge magma chambers, maintain the sill geometry through their lifetimes. For a sill to function as a magma chamber, certain conditions must be met: (1) The sill thickness must be in the order of tens of metres. This thickness is reached by either a) when a complex of thinner sills amalgamates or b) magma accumulates due to multiple dyke arrests at the contact with the sill. (2) The sill must receive a fairly constant magma replenishment so the chamber remains partially or (more rarely) totally molten. Here, we present numerical models based on geophysical data on how an individual sill can evolve into a magma chamber. Sills generally exhibit a concave-upward or straight geometry, although they may take other forms e.g. stepped, saucer-shaped, or concave-downward. Seismic studies suggest that many shallow ocean-ridge magma chambers have a moderately smooth geometry (ellipsoidal) rather than an irregular network of dykes and sills. Our numerical results indicate as follows: Firstly, the deflection of dykes into sills is most favoured in the upper crust where there are many layers generating stress barriers/delaminations due to elastic mismatch, that is, contrasting mechanical properties. Secondly, a sill grows primarily by elastic-plastic deformation of the host rock in which it is emplaced, while host rock anatexis/stoping may generate space for some large sills. The elastic-plastic expansion is partly reflected in upward bending of the overburden and partly in downward bending of the underburden. Thirdly, while the initial sill stays liquid or 'soft', subsequent dyke injections become arrested at the contact with the sill and their magmas become partly absorbed into the sill, which thereby grows. Fourthly, the sill must remain totally or at least partially molten, which requires a high injection rate of dykes feeding the sills to have a chance of developing into a shallow magma chamber. A high dyke injection rate is most likely to be reached at high extension rates, such as at fast-spreading ridges. This may be one reason for the common sill-like magma chambers being located at fast-spreading ridges.

  20. Health Facilities

    MedlinePLUS

    Health facilities are places that provide health care. They include hospitals, clinics, outpatient care centers, and specialized care centers, such as birthing centers and psychiatric care centers. When you ...

  1. FACILITY DATABASE

    Cancer.gov

    LASP Administrative Use Only Data Entry Start Date _______________ July 2007 LASP FACILTY Database Form 1.000 FACILITY DATABASE Principal Investigator – Data Entry Requirements This form is used to identify the level of data that each investigator

  2. Research Facilities

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Donald E. Bohringer, Argonne engineering specialist employed NASA information in two projects associated with the laboratory's Intense Pulsed Neutron Source (IPNS) facility. The NASA technology Bohringer employed involved improved vibration protection for a gamma ray detector in one project, and in the other a new leak detection technology. IPNS and other Argonne facilities have many vacuum and pressure vessels and early detection of leaks is highly important. Bohringer learned of both items in Tech Briefs.

  3. Simulation, design, and construction of a 137Cs irradiation facility.

    PubMed

    Studenski, Matthew T; Haverland, Nathan P; Kearfott, Kimberlee J

    2007-05-01

    Regulatory entities require that for any radiation facility the surrounding areas must be restricted unless the dose equivalent is less than 0.02 mSv in any one hour. Two Monte Carlo radiation transport simulation codes, MCNP5 and Mercurad, were used to design a facility to shield a 3.48 x 10(5) MBq 137Cs irradiator that meets these requirements. Simulations showed that the dose equivalent rates were below the legal limit for unrestricted access and the facility was constructed using available concrete block and student labor to minimize costs. To verify the accuracy of the Monte Carlo radiation transport codes, an ion chamber was used to characterize the facility. Ion chamber measurements in the actual, as-built irradiation facility showed that the Monte Carlo codes, MCNP5 and Mercurad, agreed by a factor of better than 6% and better than 11%, respectively. PMID:17440327

  4. Large-Area Neutron Detector based on Li6 Pulse Mode Ionization Chamber

    Microsoft Academic Search

    K. Chung; K. D. Ianakiev; M. T. Swinhoe; M. F. Makela

    2005-01-01

    Prototypes of a Li-6 Pulse Mode Ionization Chamber (LiPMIC) have been in development for the past two years for the purpose of providing large-area neutron detector. this system would be suitable for remote deployment for homeland security and counterterrorism needs at borders, ports, and nuclear facilities. A prototype of LiPMIC is expected to provide a similar level of performance to

  5. Characteristics of a delay-line readout in a cylindrical drift chamber system

    NASA Astrophysics Data System (ADS)

    Barber, R.; Ahmed, M. W.; Dzemidzic, M.; Empl, A.; Hungerford, E. V.; Lan, K. J.; Wilson, J.; Cooper, M. D.; Gagliardi, C. A.; Haim, D.; Kim, G. J.; Koetke, D. D.; Tribble, R. E.; Van Ausdeln, L. A.

    2002-03-01

    This paper reports on the design, construction, and operational characteristics of a delay-line readout implemented on the cathode foils of a cylindrical drift chamber system. The readout was used to determine the position of an event along the length of the 1.74 m drift wires in the MEGA detectors used at the Los Alamos Meson Physics Facility. The performance of the system is interpreted by comparison to a PSPICE simulation, and to simple analytical models.

  6. Measurements of a 1/4-scale model of an explosives firing chamber

    SciTech Connect

    Pastrnak, J.W.; Baker, C.F.; Simmons, L.F.

    1995-01-27

    In anticipation of increasingly stringent environmental regulations, Lawrence Livermore National Laboratory (LLNL) proposes to construct a 60-kg firing chamber to provide blast-effects containment for most of its open-air, high-explosive, firing operations. Even though these operations are within current environmental limits, containment of the blast effects and hazardous debris will further drastically reduce emissions to the environment and minimize the generated hazardous waste. The major design consideration of such a chamber is its overall structural dynamic response in terms of long-term containment of all blast effects from repeated internal detonations of high explosives. Another concern is how much other portions of the facility outside the firing chamber must be hardened to ensure personnel protection in the event of an accidental detonation while the chamber door is open. To assess these concerns, a 1/4-scale replica model of the planned contained firing chamber was designed, constructed, and tested with scaled explosive charges ranging from 25 to 125% of the operational explosives limit of 60 kg. From 16 detonations of high explosives, 880 resulting strains, blast pressures, and temperatures within the model were measured to provide information for the final design. Factors of safety for dynamic yield of the firing chamber structure were calculated and compared to the design criterion of totally elastic response. The rectangular, reinforced-concrete chamber model exhibited a lightly damped vibrational response that placed the structure in alternating cycles of tension and compression. During compression, both the reinforcing steel and the concrete remained elastic.

  7. Spar buoy construction having production and oil storage facilities and method of operation

    SciTech Connect

    Daniell, A.F.

    1986-08-19

    This patent describes a floating structure including oil storage capacity and production facilities and adapted to be anchored by catenary mooring lines at a subsea well location, the combination of: a vertical elongated hull means having means to maintain the hull means in vertical position; the hull means including a vertical oil storage chamber means for storing oil and extending for a major portion of the height of the floating structure; vertical variable ballast chamber means extending from the bottom of the storage chamber means to above the top of the oil storage chamber means and selectively filled with ballast to maintain the center of gravity of the structure a selected distance from the center of buoyancy of the structure; work chamber means in the hull means above the oil storage chamber means; means in the work chamber means and in the variable ballast chamber means for controlling the amount of ballast in the variable ballast means; means in the oil storage chamber means and in the work chamber means for feeding oil to the oil storage chamber means and for removing water therefrom as oil is introduced therein; a central longitudinal passageway through the hull means; a riser means extending into the passageway from the subsea well location and terminating at the work chamber means; means on the riser buoyant tank means and on the hull means in the central passageway for guiding relative movement between the hull means and the riser means.

  8. An encoding readout method used for Multi-gap Resistive Plate Chambers (MRPCs) for muon tomography

    NASA Astrophysics Data System (ADS)

    Yue, X.; Zeng, M.; Wang, Y.; Wang, X.; Zeng, Z.; Zhao, Z.; Cheng, J.

    2014-09-01

    A muon tomography facility has been built in Tsinghua University. Because of the low flux of cosmic muon, an encoding readout method, based on the fine-fine configuration, was implemented for the 2880 channels induced signals from the Multi-gap Resistive Plate Chamber (MRPC) detectors. With the encoding method, the number of the readout electronics was dramatically reduced and thus the complexity and the cost of the facility was reduced, too. In this paper, the details of the encoding method, and the overall readout system setup in the muon tomography facility are described. With the commissioning of the facility, the readout method works well. The spatial resolution of all MRPC detectors are measured with cosmic muon and the preliminary imaging result are also given.

  9. Main Chamber Pressure why do we care about it?

    E-print Network

    Pitcher, C. S.

    Main Chamber Pressure why do we care about it? - neutrals in the main chamber imply a particle-surface interaction there which may result in impurity production and erosion - neutrals in the main chamber may.main chamber recycling 3.ion flux to the upper part of the outer plate 4.upper divertor leakage #12

  10. Chapter 7.31 Centura 3-5 Chamber

    E-print Network

    Healy, Kevin Edward

    after post Al Etch passivation/resist strip process 4.4 Ch C: Chamber C; designation of DPS MET Al etch to use this chamber. 4.5 Ch D: Chamber D; designation of post Al etch passivation/resist STRIP process-5 is a reconfigured etch chamber. It has the capability to etch several materials and is capable of processing 3

  11. NSTAR Extended Life Test Discharge Chamber Flake Analysis

    NASA Technical Reports Server (NTRS)

    deGroh, Kim K.; Banks, Bruce A.; Karniotis, Christina A.

    2005-01-01

    The Extended Life Test (ELT) of the NASA Solar Electric Propulsion Technology Readiness (NSTAR) ion thruster was concluded after 30,352 hours of operation. The ELT was conducted using the Deep Space 1 (DS1) back-up flight engine, a 30 cm diameter xenon ion thruster. Post-test inspection of the ELT engine revealed numerous contaminant flakes distributed over the bottom of the cylindrical section of the anode within the discharge chamber (DC). Extensive analyses were conducted to determine the source of the particles, which is critical to the understanding of degradation mechanisms of long life ion thruster operation. Analyses included: optical microscopy (OM) and particle length histograms, field emission scanning electron microscopy (FESEM) combined with energy dispersive spectroscopy (EDS), and atomic oxygen plasma exposure tests. Analyses of the particles indicate that the majority of the DC flakes consist of a layered structure, typically with either two or three layers. The flakes comprising two layers were typically found to have a molybdenum-rich (Mo-rich) layer on one side and a carbon-rich (C-rich) layer on the other side. The flakes comprising three layers were found to be sandwich-like structures with Mo-rich exterior layers and a C-rich interior layer. The presence of the C-rich layers indicates that these particles were produced by sputter deposition build-up on a surface external to the discharge chamber from ion sputter erosion of the graphite target in the test chamber. This contaminant layer became thick enough that particles spalled off, and then were electro-statically attracted into the ion thruster interior, where they were coated with Mo from internal sputter erosion of the screen grid and cathode components. Atomic oxygen tests provided evidence that the DC chamber flakes are composed of a significant fraction of carbon. Particle size histograms further indicated that the source of the particles was spalling of carbon flakes from downstream surfaces. Analyses of flakes taken from the downstream surface of the accelerator grid provided additional supportive information. The production of the downstream carbon flakes, and hence the potential problems associated with the flake particles in the ELT ion thruster engine is a facility induced effect and would not occur in the space environment.

  12. Organization of inspection of bubble chamber photographs

    SciTech Connect

    Gritsaenko, I.A.; Fenyuk, A.B.; Petrovykh, L.P.; Petrovykh, Yu.L.

    1986-03-01

    A program for inspection of bubble chamber photographs is described. The program was developed for a DEC-10 computer and is designed for PUOS-2M and PUOS-4 semiautomatic inspection and measuring projectors. Formalization of the inspection procedure allows it to be used for various physics experiments. As an example the authors consider the problem of the physical inspection in an experiment on scattering of kaons plus with momenta of 70 GeV/c by protons performed in a BEBC chamber. Primary vertices were analyzed in the following cases: low quality of reconstruction of parameters in the geometric program; lack of agreement of the number of reconstructed tracks with that indicated by inspection; and unmeasured events and events with candidate tracks for identification of proton tracks by degree of ionization. The performance of the program in these cases is evaluated. The program has been used to process 50,000 events recorded with a BEBC chamber as well as experiments recorded with the SCAT chamber and the European Hybrid Spectrometer using the RCBC, LEBC and HOLEBC chambers.

  13. The construction of the KLOE drift chamber: Present status KLOE Drift Chamber Group

    NASA Astrophysics Data System (ADS)

    Valente, Paolo; Andryakov, A.; Antonelli, A.; Baldini-Ferroli, R.; Bencivenni, G.; Bucci, L.; Calcaterra, A.; Campana, P. L.; Dell'Agnello, S.; de Sangro, R.; De Simone, P.; Felici, G.; Finocchiaro, G.; Forti, C.; Moccia, S.; Passalacqua, L.; Patera, V.; Piccolo, M.; Kulikov, V.; Nedosekin, A.; Cataldi, G.; Denig, A.; Kluge, W.; Von Hagel, U.; Weseler, S.; Elia, V.; Golovatyuk, V.; Gorini, E.; Grancagnolo, F.; Panareo, M.; Primavera, M.; Spagnolo, S.; De Lucia, E.; Lacava, F.; Luisi, C.; Picca, D.; Pontecorvo, L.; Messi, R.; Paoluzi, L.; Valente, P.; Bacci, C.; Ceradini, F.

    1998-02-01

    The status of the construction of the KLOE Drift Chamber is reviewed. With its 4 m diameter, it will be the biggest drift chamber ever built. The stringing of 52 000 wires is a titanic effort: details are given about the semiautomatic system, the quality tests on wires and the monitoring of end-plates deformations.

  14. Design characteristics of a 100 kV, 100 kW plasma ion implantation facility

    Microsoft Academic Search

    J. N. Matossian; D. M. Goebel

    1996-01-01

    The design characteristics of the 100 kV, 100 kW plasma ion implantation (PII) facility at Hughes Research Laboratories are described. The facility is comprised of a vacuum chamber in which parts are implanted and a pulse modulator which provides voltage pulses to implant ions into parts. The vacuum chamber is a horizontally-mounted, 4 ft diameter × 8 ft long, stainless-steel

  15. Cryogenic Test Capability at Marshall Space Flight Center's X-ray Cryogenic Test Facility

    NASA Technical Reports Server (NTRS)

    Kegley, Jeffrey; Baker, Mark; Carpenter, Jay; Eng, Ron; Haight, Harlan; Hogue, William; McCracken, Jeff; Siler, Richard; Wright, Ernie

    2006-01-01

    Marshall Space Flight Center's X-ray & Cryogenic Test Facility (XRCF) has been performing sub-liquid nitrogen temperature testing since 1999. Optical wavefront measurement, thermal structural deformation, mechanism functional & calibration, and simple cryo-conditioning tests have been completed. Recent modifications have been made to the facility in support of the James Webb Space Telescope (JWST) program. The chamber's payload envelope and the facility s refrigeration capacity have both been increased. Modifications have also been made to the optical instrumentation area improving access for both the installation and operation of optical instrumentation outside the vacuum chamber. The facility's capabilities, configuration, and performance data will be presented.

  16. On-Site Wastewater Treatment Systems: Leaching Chambers

    E-print Network

    Lesikar, Bruce J.

    2000-02-04

    Two-compartment septic tank Leaching chamber Soil absorption field On-site wastewater treatment systems Leaching chambers Bruce Lesikar and Russell Persyn Extension Agricultural Engineering Specialist, Extension Assistant-Water Conservation.... The main difference is in how the trench is constructed. A leaching chamber system includes: 3 A treatment device, generally a septic tank, but it can be an advanced treatment system. 3 A leaching chamber, which is a commercially available plastic chamber...

  17. Exhaust gas reaction chambers for internal combustion engine

    Microsoft Academic Search

    Y. Sakurai; T. Okura; M. Tanaka

    1979-01-01

    An internal-combustion spark-ignition V-8 piston engine has a main exhaust gas reaction chamber positioned between the two banks of cylinders. Each cylinder has a main combustion chamber and an auxiliary combustion chamber connected by a torch nozzle restriction. Valved intake passages supply lean mixture to the main combustion chambers and rich mixture to the auxiliary combustion chamber. Valved exhaust passages

  18. On-Site Wastewater Treatment Systems: Leaching Chambers 

    E-print Network

    Lesikar, Bruce J.

    2000-02-04

    Two-compartment septic tank Leaching chamber Soil absorption field On-site wastewater treatment systems Leaching chambers Bruce Lesikar and Russell Persyn Extension Agricultural Engineering Specialist, Extension Assistant-Water Conservation.... The main difference is in how the trench is constructed. A leaching chamber system includes: 3 A treatment device, generally a septic tank, but it can be an advanced treatment system. 3 A leaching chamber, which is a commercially available plastic chamber...

  19. Drift chamber tracking with neural networks

    SciTech Connect

    Lindsey, C.S.; Denby, B.; Haggerty, H. (Fermi National Accelerator Lab., Batavia, IL (United States))

    1993-08-01

    With the very high event rates projected for experiments at the SSC and LHC, it is important to investigate new approaches to on line pattern recognition. The use of neural networks for pattern recognition. The use of neural networks for pattern recognition in high energy physics detectors has been an area of very active research. The authors discuss drift chamber tracking with a commercial analog VLSI neural network chip. Voltages proportional to the drift times in a 4-layer drift chamber were presented to the Intel ETANN chip. The network was trained to provide the intercept and slope of straight tracks traversing the chamber. The outputs were recorded and later compared off line to conventional track fits. Two types of network architectures were studied. Applications of neural network tracking to high energy physics detector triggers is discussed.

  20. Secondary organic aerosol formation from gasoline vehicle emissions in a new mobile environmental reaction chamber

    NASA Astrophysics Data System (ADS)

    Platt, S. M.; El Haddad, I.; Zardini, A. A.; Clairotte, M.; Astorga, C.; Wolf, R.; Slowik, J. G.; Temime-Roussel, B.; Marchand, N.; Ježek, I.; Drinovec, L.; Mo?nik, G.; Möhler, O.; Richter, R.; Barmet, P.; Bianchi, F.; Baltensperger, U.; Prévôt, A. S. H.

    2012-10-01

    We present a new mobile environmental reaction chamber for the simulation of the atmospheric aging of aerosols from different emissions sources without limitation from the instruments or facilities available at any single site. The chamber can be mounted on a trailer for transport to host facilities or for mobile measurements. Photochemistry is simulated using a set of 40 UV lights (total power 4 KW). Characterisation of the emission spectrum of these lights shows that atmospheric photochemistry can be accurately simulated over a range of temperatures from -7-25 °C. A photolysis rate of NO2, JNO2, of (8.0 ± 0.7) × 10-3 molecules cm-3 s-1 was determined at 25 °C. Further, we present the first application of the mobile chamber and demonstrate its utility by quantifying primary organic aerosol (POA) emission and secondary organic aerosol (SOA) production from a Euro 5 light duty gasoline vehicle. Exhaust emissions were sampled during the New European Driving Cycle (NEDC), the standard driving cycle for European regulatory purposes, and injected into the chamber. The relative concentrations of oxides of nitrogen (NOx) and total hydrocarbon (THC) during the aging of emissions inside the chamber were controlled using an injection system developed as a part of the new mobile chamber set up. Total OA (POA + SOA) emission factors of (370 ± 18) × 10-3 g kg-1 fuel, or (14.6 ± 0.8) × 10-3 g km-1, after aging, were calculated from concentrations measured inside the smog chamber during two experiments. The average SOA/POA ratio for the two experiments was 15.1, a much larger increase than has previously been seen for diesel vehicles, where smog chamber studies have found SOA/POA ratios of 1.3-1.7. Due to this SOA formation, carbonaceous particulate matter (PM) emissions from a gasoline vehicle may approach those of a diesel vehicle of the same class. Furthermore, with the advent of emission controls requiring the use of diesel particle filters, gasoline vehicle emissions could become a far larger source of ambient PM than diesel vehicles. Therefore this large increase in the PM mass of gasoline vehicle aerosol emissions due to SOA formation has significant implications for our understanding of the contribution of on-road vehicles to ambient aerosols and merits further study.

  1. Simulation of BaBar Drift Chamber

    SciTech Connect

    Anderson, Rachel; /Wisconsin U., Eau Claire /SLAC

    2006-09-27

    The BaBar drift chamber (DCH) is used to measure the properties of charged particles created from e{sup +}e{sup -} collisions in the PEP-II asymmetric-energy storage rings by making precise measurements of position, momentum and ionization energy loss (dE/dx). In October of 2005, the PEP-II storage rings operated with a luminosity of 10 x 10{sup 33} cm{sup -2}s{sup -1}; the goal for 2007 is a luminosity of 20 x 10{sup 33} cm{sup -2}s{sup -1}, which will increase the readout dead time, causing uncertainty in drift chamber measurements to become more significant in physics results. The research described in this paper aims to reduce position and dE/dx uncertainties by improving our understanding of the BaBar drift chamber performance. A simulation program--called GARFIELD--is used to model the behavior of the drift chamber with adjustable parameters such as gas mixture, wire diameter, voltage, and magnetic field. By exploring the simulation options offered in GARFIELD, we successfully produced a simulation model of the BaBar drift chamber. We compared the time-to-distance calibration from BaBar to that calculated by GARFIELD to validate our model as well as check for discrepancies between the simulated and calibrated time-to-distance functions, and found that for a 0{sup o} entrance angle there is a very good match between calibrations, but at an entrance angle of 90{sup o} the calibration breaks down. Using this model, we also systematically varied the gas mixture to find one that would optimize chamber operation, which showed that the gas mixture of 80:20 Helium:isobutane is a good operating point, though more calculations need to be done to confirm that it is the optimal mixture.

  2. Quasi-Porous Plug With Vortex Chamber

    NASA Technical Reports Server (NTRS)

    Walsh, J. V.

    1985-01-01

    Pressure-letdown valve combines quasi-porous-plug and vortex-chamber in one controllable unit. Valve useful in fossil-energy plants for reducing pressures in such erosive two-phase process streams as steam/water, coal slurries, or combustion gases with entrained particles. Quasi-Porous Plug consists of plenums separated by perforated plates. Number or size of perforations increases with each succeeding stage to compensate for expansion. In Vortex Chamber, control flow varies to control swirl and therefore difference between inlet and outlet pressures.

  3. A bombardment chamber for PIXE analyses

    NASA Astrophysics Data System (ADS)

    Norman, L.; Jensen, B.; Bauman, S. E.; Houmere, P. D.; Nelson, J. W.

    1984-04-01

    A target chamber for PIXE irradiations is described. This compact aluminum chamber has a small volume for rapid evacuation and a short (30 mm) target to detector distance. Beam collimators and detector filter/collimators are changed simultaneously by rotating either a six or nine position disc. A circular array of eight 25 mm diameter targets or an 82 mm diameter sample holding frame is rotated by a 192 step solenoid-operated ratchet which also functions as an angular position encoder. Other options include provisions for mounting a particle backscatter detector, backfill with helium gas, and vertical variation of target position by motor driven cam.

  4. Thermistors Used in Climatic Chamber at High Temperature and Humidity

    NASA Astrophysics Data System (ADS)

    van Geel, J. L. W. A.; Bosma, R.; van Wensveen, J.; Peruzzi, A.

    2015-03-01

    In 2011, VSL initiated the development of a facility for a relative humidity between and for calibrating high-temperature relative humidity sensors at pressures other than atmospheric. The setup for calculating the relative humidity uses the dew-point temperature, measured by a chilled mirror hygrometer, and the temperature distribution in the chamber, measured by a series of thermistors. This paper describes the results of thermal tests performed on the thermistors to ensure that they meet the requirements of the humidity calibration facility. Different types of thermistors were evaluated up to , and the selected type showed a short-term drift of less than 2 mK. Exposure of these thermistors to temperatures up to gave an initial hysteresis of 40 mK, but after this initial hysteresis, the hysteresis, over the range from up to , was less than 10 mK. Use of a digital multimeter, with a low-power option, limited the self-heating of the thermistors, over the range from up to , to less than 5 mK. During use in the new setup, the thermistors were exposed to changing humidities between 1 %Rh and 90 %Rh and temperatures up to , showing drifts of less than 10 mK.

  5. The space simulation facilities at IAL SPACE

    NASA Technical Reports Server (NTRS)

    Henrist, M.; Cucchiaro, A.; Domken, I.; Macau, J. P.

    1990-01-01

    The thermal vacuum facilities of IAL SPACE were tailored for testing of the ESA payloads. They were progressively upgraded for cryogenic payloads including 4 K (liquid helium temperature) experiments. A detailed review of the three vacuum chambers, ranging from 1.5 to 5 m diameter, is presented including the corresponding capabilities in the vacuum, thermal, and optical fields. The various aspects of cleanliness, product assurance, and quality control are also presented.

  6. Mammography Facilities

    MedlinePLUS

    ... A to Z Index Follow FDA En Español Enter Search terms Home Food Drugs Medical Devices Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products ... Search Mammography Facilities Help | Download File | More About MQSA Enter the First 3 Digits of your Zip Code ...

  7. The New LOTIS Test Facility

    NASA Technical Reports Server (NTRS)

    Bell, R. M.; Cuzner, G.; Eugeni, C.; Hutchison, S. B.; Merrick, A. J.; Robins, G. C.; Bailey, S. H.; Ceurden, B.; Hagen, J.; Kenagy, K.; Martin, H. M.; Tuell, M.; Ward, M.; West, S. C.

    2008-01-01

    The Large Optical Test and Integration Site (LOTIS) at the Lockheed Martin Space Systems Company in Sunnyvale, CA is designed for the verification and testing of optical systems. The facility consists of an 88 foot temperature stabilized vacuum chamber that also functions as a class 10k vertical flow cleanroom. Many problems were encountered in the design and construction phases. The industry capability to build large chambers is very weak. Through many delays and extra engineering efforts, the final product is very good. With 11 Thermal Conditioning Units and precision RTD s, temperature is uniform and stable within 1oF, providing an ideal environment for precision optical testing. Within this chamber and atop an advanced micro-g vibration-isolation bench is the 6.5 meter diameter LOTIS Collimator and Scene Generator, LOTIS alignment and support equipment. The optical payloads are also placed on the vibration bench in the chamber for testing. This optical system is designed to operate in both air and vacuum, providing test imagery in an adaptable suite of visible/near infrared (VNIR) and midwave infrared (MWIR) point sources, and combined bandwidth visible-through-MWIR point sources, for testing of large aperture optical payloads. The heart of the system is the LOTIS Collimator, a 6.5m f/15 telescope, which projects scenes with wavefront errors <85 nm rms out to a 0.75 mrad field of view (FOV). Using field lenses, performance can be extended to a maximum field of view of 3.2 mrad. The LOTIS Collimator incorporates an extensive integrated wavefront sensing and control system to verify the performance of the system.

  8. Acoustical-Levitation Chamber for Metallurgy

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Trinh, E.; Wang, T. G.; Elleman, D. D.; Jacobi, N.

    1983-01-01

    Sample moved to different positions for heating and quenching. Acoustical levitation chamber selectively excited in fundamental and second-harmonic longitudinal modes to hold sample at one of three stable postions: A, B, or C. Levitated object quickly moved from one of these positions to another by changing modes. Object rapidly quenched at A or C after heating in furnace region at B.

  9. HERL BIOLOGICAL EXPOSURE CHAMBER CONCEPTUAL DESIGN

    EPA Science Inventory

    Because of the current interest in biotesting of potentially hazardous air pollutants, the Health Effects Research Laboratory (HERL) of EPA/RTP has contracted Radian to design biological exposure chambers that can be used to expose text organisms to the secondary aerosol effluent...

  10. Internal combustion engine with dual combustion chambers

    Microsoft Academic Search

    Simay

    1987-01-01

    This patent describes a spark-ignition. The overhead valve type internal combustion engine comprises: a cylinder closed at the top by a semi-spherical cylinder head; a piston reciprocating within the cylinder with the piston; cylinder and cylinder head defining at least one combustion chamber; and wherein the cylinder head includes an intake valve aperture, an exhaust valve aperture, and a spark

  11. PAINT COATINGS: CONTROLLED FIELD AND CHAMBER EXPERIMENTS

    EPA Science Inventory

    To determine the impact of pollution levels on the weathering rates of coatings, laboratory chamber experiments and controlled field exposures at North Carolina and Ohio sites were conducted in such a manner to separate the contributions due to dry deposition, wet deposition, pre...

  12. Multiphysics Nuclear Thermal Rocket Thrust Chamber Analysis

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See

    2005-01-01

    The objective of this effort is t o develop an efficient and accurate thermo-fluid computational methodology to predict environments for hypothetical thrust chamber design and analysis. The current task scope is to perform multidimensional, multiphysics analysis of thrust performance and heat transfer analysis for a hypothetical solid-core, nuclear thermal engine including thrust chamber and nozzle. The multiphysics aspects of the model include: real fluid dynamics, chemical reactivity, turbulent flow, and conjugate heat transfer. The model will be designed to identify thermal, fluid, and hydrogen environments in all flow paths and materials. This model would then be used to perform non- nuclear reproduction of the flow element failures demonstrated in the Rover/NERVA testing, investigate performance of specific configurations and assess potential issues and enhancements. A two-pronged approach will be employed in this effort: a detailed analysis of a multi-channel, flow-element, and global modeling of the entire thrust chamber assembly with a porosity modeling technique. It is expected that the detailed analysis of a single flow element would provide detailed fluid, thermal, and hydrogen environments for stress analysis, while the global thrust chamber assembly analysis would promote understanding of the effects of hydrogen dissociation and heat transfer on thrust performance. These modeling activities will be validated as much as possible by testing performed by other related efforts.

  13. OUTDOOR SMOG CHAMBER EXPERIMENTS USING AUTOMOBILE EXHAUST

    EPA Science Inventory

    Outdoor smog chamber experiments using automobile exhaust were performed in this study. The purpose of the study was to provide a data base that modelers could use to develop new, improved mechanisms for use in the Empirical Kinetics Modeling Approach (EKMA). Thirty-three dual sm...

  14. Miniature reaction chamber and devices incorporating same

    DOEpatents

    Mathies, Richard A. (Moraga, CA); Woolley, Adam T. (Albany, CA)

    2000-10-17

    The present invention generally relates to miniaturized devices for carrying out and controlling chemical reactions and analyses. In particular, the present invention provides devices which have miniature temperature controlled reaction chambers for carrying out a variety of synthetic and diagnostic applications, such as PCR amplification, nucleic acid hybridization, chemical labeling, nucleic acid fragmentation and the like.

  15. Presenting Chamber Music to Young Children

    ERIC Educational Resources Information Center

    Smith, Terry Fonda

    2011-01-01

    The number of professional ensembles and organizations with dedicated outreach concerts has been steadily increasing over the past decade. More recently, educational concerts pairing chamber music with young children have been documented. The work presented in this article is a study in the efficacy and feasibility of this format. Various music…

  16. Replenishment of magma chambers by light inputs

    Microsoft Academic Search

    Herbert E. Huppert; R. Stephen; J. Sparks; John A. Whitehead; Mark A. Halloworth

    1986-01-01

    Magma chambers, particularly those of basaltic composition, are often replenished by an influx of magma whose density is less than that of the resident magma. This paper describes the fundamental fluid mechanics involved in the replenishment by light inputs. If rho denotes the uniform density of the resident magma and rho-Deltarho that the input, the situation is described by the

  17. Try Chamber Music--Here's How.

    ERIC Educational Resources Information Center

    Rudaitis, Cheryl

    1995-01-01

    Profiles four middle school teachers maintaining early chamber music programs. The teachers advise varying degrees of musical competency before students begin the program, but all of them caution against starting too soon. They also stress the importance of purchasing early music scores and establishing rehearsal times. (MJP)

  18. A Theory of Diffusion Cloud Chambers

    Microsoft Academic Search

    R. P. Shutt

    1951-01-01

    An attempt is made to understand quantitatively the effects of a given gas, gas pressure, vapor, ionization density, and temperature distribution on the operation of diffusion chambers. An integral equation is set up which takes into account diffusion of the vapor through the gas, removal of vapor by condensation, drop growth, and the motion of the drops due to gravity.

  19. Wave Phenomena in an Acoustic Resonant Chamber

    ERIC Educational Resources Information Center

    Smith, Mary E.; And Others

    1974-01-01

    Discusses the design and operation of a high Q acoustical resonant chamber which can be used to demonstrate wave phenomena such as three-dimensional normal modes, Q values, densities of states, changes in the speed of sound, Fourier decomposition, damped harmonic oscillations, sound-absorbing properties, and perturbation and scattering problems.…

  20. Combustion chamber floatwall panel attachment arrangement

    Microsoft Academic Search

    C. J. Griffin

    1984-01-01

    The abstract discloses an attachment arrangement in a combustion chamber of a gas turbine powerplant, having a double wall structure formed by a separate combustor shell and at least one floatwall panel. The arrangement includes a pair of hook-like projections protruding from the panel and through the shell and a pair of thin plates for interengaging the hook-like projections on

  1. Chamber for Aerosol Deposition of Bioparticles

    NASA Technical Reports Server (NTRS)

    Kern, Roger; Kirschner, Larry

    2008-01-01

    Laboratory apparatus is depicted that is a chamber for aerosol deposition of bioparticles on surfaces of test coupons. It is designed for primary use in inoculating both flat and three-dimensional objects with approximately reproducible, uniform dispersions of bacterial spores of the genus Bacillus so that the objects could be used as standards for removal of the spores by quantitative surface sampling and/or cleaning processes. The apparatus is also designed for deposition of particles other than bacterial spores, including fungal spores, viruses, bacteriophages, and standard micron-sized beads. The novelty of the apparatus lies in the combination of a controllable nebulization system with a settling chamber large enough to contain a significant number of test coupons. Several companies market other nebulizer systems, but none are known to include chambers for deposition of bioparticles to mimic the natural fallout of bioparticles. The nebulization system is an expanded and improved version of commercially available aerosol generators that include nebulizers and drying columns. In comparison with a typical commercial aerosol generator, this system includes additional, higher-resolution flowmeters and an additional pressure regulator. Also, unlike a typical commercial aerosol generator, it includes stopcocks for separately controlling flows of gases to the nebulizer and drying column. To maximize the degree of uniformity of dispersion of bioaerosol, the chamber is shaped as an axisymmetrical cylinder and the aerosol generator is positioned centrally within the chamber and aimed upward like a fountain. In order to minimize electric charge associated with the aerosol particles, the drying column is made of aluminum, the drying column is in direct contact with an aluminum base plate, and three equally spaced Po-210 antistatic strips are located at the exit end of the drying column. The sides and top of the chamber are made of an acrylic polymer; to prevent accumulation of electric charge on them, they are spray-coated with an anti-static material. During use, the base plate and the sides and top of the chamber are grounded as a further measure to minimize the buildup of electric charge.

  2. Test plan pressure fed thrust chamber technology

    NASA Technical Reports Server (NTRS)

    Dunn, Glenn

    1990-01-01

    Aerojet is developing the technology for the design of a reliable, low cost, efficient, and lightweight LOX/RP-1 pressure fed engine. This technology program is a direct result of Aerojet's liquid rocket booster (LRB) study and previous NASA studies that identified liquid engines using high bulk density hydrocarbon fuels as very attractive for a space transportation system (STS). Previous large thrust LOX/RP-1 engine development programs were characterized by costly development problems due to combustion instability damage. The combustion stability solution was typically obtained through trial and error methods of minimizing instability damage by degrading engine performance. The approach to this program was to utilize existing and newly developed combustion analysis models and design methodology to create a thrust chamber design with features having the potential of producing reliable and efficient operation. This process resulted in an engine design with a unique high thrust-per-element OFO triplet injector utilizing a low cost modular approach. Cost efficient ablative materials are baselined for the injector face and chamber. Technology demonstration will be accomplished through a hot fire test program using appropriately sized subscale hardware. This subscale testing will provide a data base to supplement the current industry data bank and to anchor and validate the applied analysis models and design methodology. Once anchored and validated, these analysis models and design methodology can be applied with greatly increased confidence to design and characterize a large scale pressure fed LOX/RP-1 thrust chamber. The objective of this test program is to generate a data base that can be used to anchor and validate existing analysis models and design methodologies and to provide early concept demonstration of a low cost, efficient LOX/RP-1 thrust chamber. Test conditions and hardware instrumentation were defined to provide data sufficient to characterize combustion stability, performance, and thermal operation over a wide thrust chamber throttling range.

  3. DFL, Canada's Space AIT Facilities - Current and Planned Capabilities

    NASA Astrophysics Data System (ADS)

    Singhal, R.; Mishra, S.; Choueiry, E.; Dumoulin, J.; Ahmed, S.

    2004-08-01

    The David Florida Laboratory (DFL) of the Canadian Space Agency is the Canadian national ISO 9001:2000 registered facility for the assembly, integration, and (environmental) testing of space hardware. This paper briefly describes the three main qualification facilities: Structural Qualification Facilities (SQF); Radio Frequency Qualification Facilities (RFQF); and Thermal Qualification Facilities (TQF). The paper also describes the planned/new upgrades/improvements to the DFL's existing capabilities. These include: cylindrical near-field antenna measurement system, current capabilities in multi-frequency multi-band passive intermodulation (PIM) measurement; combined thermal/vibration test facility, improvement in efficiency and performance of the photogrammetry capability, acquisition of an additional mass properties measurement system for small and micro-satellites; combined control and data acquisition system for all existing thermal vacuum facilities, plus a new automatic thermal control system and hypobaric chamber.

  4. The Large Mars Atmosphere Simulation Chamber at the University of Winnipeg

    NASA Astrophysics Data System (ADS)

    Cole, S. B.; Cloutis, E.; Cuddy, M.; Izawa, M. R.; Mann, P.; Craig, M. A.; Pietrasz, V. B.; Squyres, S. W.

    2014-12-01

    We present a new Mars atmosphere simulation chamber (ME: Mars Environment) at the University of Winnipeg Planetary Spectroscopy Facility, available for community use. Our rectangular chamber is 36" wide, 25" high, and 24" deep, with a versatile design capable of accommodating powdered samples, moderately-sized instruments, and geological hand samples and exposing them to a simulated Martian atmosphere. Viewing windows span the upper front and one side, and there are two additional 10"x10" transparent ports on the front, which can be easily opened to install and manipulate apparatus prior to pumping the system down. The windows and ports, which allow for full viewing of the interior, consist of 0.75" thick polycarbonate. The chamber was fabricated from 0.5" thick Al alloy.Our system includes two externally-controlled sample wheels, each of which can hold up to 16 one-inch diameter samples. The samples can be viewed from above through a pair of windows for spectroscopic analysis. In our current configuration, one window above each wheel is ZnS and the other is sapphire, but these can be easily exchanged with other materials to suit various wavelength transmission ranges. One sample wheel is in thermal contact with copper tubing for heating or cooling; the wheel is removable and the tubing manifold can be configured to hold a hand sample for spectroscopic analysis under a controlled temperature and Martian atmospheric pressure.The chamber is large enough to accommodate instruments under consideration for landed missions. A 24-wire electrical pass through enables applications such as powering instruments or monitoring chamber properties (temperatures, atmospheric pressure, etc.).The chamber is available for national and international collaborations and can be used to support a diversity of projects. Our commissioning experiment involves examining the medium-term (several weeks) stability of various water-bearing minerals exposed to Martian surface conditions.

  5. Anterior chamber fixation of a posterior chamber intraocular lens: A novel technique

    PubMed Central

    Kükner, A ?ahap; Alagöz, Gürsoy; Erdurmu?, Mesut; Serin, Didem; Do?an, Ümit; Y?lmaz, Turgut

    2014-01-01

    We aimed to evaluate the implantation of a posterior chamber intraocular lens (IOL) in the anterior chamber (AC) with the haptics passing through two iridectomies to the posterior chamber. A total of 33 eyes of 33 patients with inadequate posterior capsular support due to either previous aphakia or posterior capsular rupture during cataract extraction were included in the study. A double iridectomy was performed on all patients using a vitrectomy probe on the midperiphery of the iris. IOLs were implanted in the AC, and the haptics were passed through the iridectomies to the posterior chamber. The mean follow-up time was 25.3 months. AC hemorrhage occurred in five patients during the iridectomy procedure. Corneal edema was detected in eight of 14 patients with primary IOL insertions. Haptic dislocation was detected in only one patient. This technique may be a good alternative to scleral-fixated IOL implantation in eyes with aphakia. PMID:24817750

  6. A combination drift chamber\\/pad chamber for very high readout rates

    Microsoft Academic Search

    L. Spiegel; G. Cataldi; V. Elia; P. Mazur; C. T. Murphy; R. P. Smith; W. Yang; T. Alexopoulos; C. Durandet; A. Erwin; J. Jennings; L. Antoniazzi; G. Introzzi; A. Lanza; G. Liguori; P. Torre; M. Arenton; S. Conetti

    1991-01-01

    Six medium-sized (â1 à 2 m²) drift chambers with pad and stripe readout have been constructed for and are presently operating in Fermi National Accelerator Laboratory experiment E-771. Each chamber module actually represents a pair of identical planes: two sets of anode wires, two sets of stripes, and two sets of pads. The wire planes are read out separately and

  7. Achievable field strength in reverberation chambers

    NASA Astrophysics Data System (ADS)

    Eulig, N.; Enders, A.; Krauthäuser, H. G.; Nitsch, J.

    2003-05-01

    Feldvariable Kammern (FVK, engl.: modestirred- chamber) werden unter anderem für EMV-Störfestigkeitsprüfungen verwendet. Ein häufig genanntes Argument, das die Einführung dieser Kammern als normgerechte Prüfumgebung vorantreiben soll, ist eine hohe Feldstärke, die im Vergleich zu anderen Testumgebungen mit relativ moderaten HF-Leistungen erreicht werden kann. Besonders für sicherheitskritische Geräte, wie Komponenten aus der Avionik- oder KFZ-Industrie, sind heutzutage Testfeldstärken von mehreren 100 V/m notwendig. Derart hohe Feldstärken können in Umgebungen, die ein ebenes Wellenfeld erzeugen oder nachbilden, nur mit großen HFLeistungen generiert werden. Durch die Resonanzeigenschaften einer FVK können demgegenüber mit sehr viel weniger Leistung und damit Verstärkeraufwand vergleichbare Werte der Feldstärke erzeugt werden. Allerdings sinkt mit zunehmendem Volumen die erreichbare Feldstärke bei gleicher Speiseleistung. Idealerweise sollen Feldvariable Kammern bei möglichst niedrigen Frequenzen für EMVTests nutzbar sein, was jedoch ein großes Kammervolumen erfordert. Das Problem, bei niedrigen Frequenzen hohe Feldstärken erzeugen zu können, relativiert deshalb den Vorteil von FVKn gegenüber bekannten Testumgebungen bei niedrigen Testfrequenzen. Der Posterbeitrag erläutert, welche Feldstärken in verschieden großen Feldvariablen Kammern beim Einspeisen einer bestimmten hochfrequenten Leistung erreicht werden können. Anhand dieser Ergebnisse wird aufgezeigt, oberhalb welcher Grenzfrequenz eine Anwendung von FVKn nur sinnvoll erscheint. Mode-stirred chambers (MSCs) can be used for radiated immunity tests in EMC testing. Advantageous compared to conventional test methods is the high field strength which can here be generated with less RF-Power. This point is often the main argument for pushing the standardization of MSCs as an other EMC testing environment. Especially for safety-critical electronic equipment like avionic or automotive systems, immunity tests with field strengths of several 100 V/m are necessary. Such high field strengths can only be generated with substantial RF power and therefore expensive amplifiers if the test is performed in an environment with plane waves. Due to resonance effects in mode-stirred chambers, comparable values of the field strength can there be obtained with significantly less power. In these chambers the field strength declines with increasing volume for a constant input power. As an ideal testing environment a mode-stirred chamber should also work at low frequencies which requires a large volume, however. Hence there is a contradiction between generating high level field strengths on the one hand and obtaining a lowest usable frequency of several 10 MHz on the other. This relativizes the advantage of generating high field strengths with less power if the chamber is supposed to work down to low frequencies. This article deals with the field strengths that can be obtained in mode-stirred chambers with a certain size. Data of different mode-stirred chambers are compared. From this a frequency limit can be derived, above which the use a mode-stirred chamber for achieving high field strengths seems meaningful only.

  8. Facilities for studing radiation damage in nonmetals during irradiation

    Microsoft Academic Search

    P. W. Levy

    1984-01-01

    Two facilities were developed for making optical absorption, luminescence and other measurements on a single sample before, during and after irradiation. One facility uses Co-60 gamma rays and the other 0.5 to 3 MeV electrons from an accelerator. Optical relays function as spectrophotometers, luminescence detectors, etc. All radiation sensitive components are outside of walk-in irradiation chambers; all measurement control and

  9. Space power facility for testing large space optical systems

    Microsoft Academic Search

    Jerry Carek

    2006-01-01

    The space power facility is located at NASA's Glenn Research Center Plum Brook Station in Sandusky, Ohio. It is the world's largest space simulation test facility with a test chamber that is 30.5m (100ft) in diameter by 37.2m (122ft) high. It has been used to test a variety of large space flight hardware and space systems for NASA, other government

  10. Status of the National Ignition Facility and Control System

    Microsoft Academic Search

    P J Van Arsdall; R M Bryant; R W Carey; D D Casavant; L J Lagin; R W Patterson

    2005-01-01

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility under construction that will contain a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for multiple experimental diagnostics. NIF will be the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement

  11. Improved chamber for the isolation of anaerobic microorganisms.

    PubMed Central

    Cox, M E; Mangels, J I

    1976-01-01

    A small portable chamber for the recovery of anaerobic bacteria is described. This rigid chamber is constructed of clear acrylic with dimensions of 30 inches (ca. 76.2 cm) wide, 18 inches (ca. 44.7 cm) deep, and 18 inches (ca. 44.7 cm) high. Conventional bacteriological techniques can be used inside the chamber to efficiently isolate strict anaerobic organisms. An adapter allows the attachment of a standard anaerobic jar to the outside of the chamber. The jar can be used to store reduced media. Once the jar is attached to the chamber and the media is removed to the interior of the chamber, the jar is available to receive inoculated media. The anaerobic jar can then be removed from the chamber, without contaminating the jar or chamber with oxygen, and be placed in a conventional 37degreesC incubator. This chamber also allows the microbiologist to process cultures without wearing gloves as was necessary with previous anaerobic chambers. Air-tight latex rubber sleeves seal around the microbiologists arms and to the armport flange of the chamber to prevent the introduction of oxygen into the chamber. Anaerobic conditions are maintained by circulating a 80% N2, 10% H2, 10% CO2 gas mixture through alumina pellets coated with palladium. This study indicates that anaerobic conditions obtained in this chamber are sufficient for recovery of obligate anaerobes. PMID:783188

  12. Europlanet Research Infrastructure: Planetary Simulation Facilities

    NASA Astrophysics Data System (ADS)

    Davies, G. R.; Mason, N. J.; Green, S.; Gómez, F.; Prieto, O.; Helbert, J.; Colangeli, L.; Srama, R.; Grande, M.; Merrison, J.

    2008-09-01

    EuroPlanet The Europlanet Research Infrastructure consortium funded under FP7 aims to provide the EU Planetary Science community greater access for to research infrastructure. A series of networking and outreach initiatives will be complimented by joint research activities and the formation of three Trans National Access distributed service laboratories (TNA's) to provide a unique and comprehensive set of analogue field sites, laboratory simulation facilities, and extraterrestrial sample analysis tools. Here we report on the infrastructure that comprises the second TNA; Planetary Simulation Facilities. 11 laboratory based facilities are able to recreate the conditions found in the atmospheres and on the surfaces of planetary systems with specific emphasis on Martian, Titan and Europa analogues. The strategy has been to offer some overlap in capabilities to ensure access to the highest number of users and to allow for progressive and efficient development strategies. For example initial testing of mobility capability prior to the step wise development within planetary atmospheres that can be made progressively more hostile through the introduction of extreme temperatures, radiation, wind and dust. Europlanet Research Infrastructure Facilties: Mars atmosphere simulation chambers at VUA and OU These relatively large chambers (up to 1 x 0.5 x 0.5 m) simulate Martian atmospheric conditions and the dual cooling options at VUA allows stabilised instrument temperatures while the remainder of the sample chamber can be varied between 220K and 350K. Researchers can therefore assess analytical protocols for instruments operating on Mars; e.g. effect of pCO2, temperature and material (e.g., ± ice) on spectroscopic and laser ablation techniques while monitoring the performance of detection technologies such as CCD at low T & variable p H2O & pCO2. Titan atmosphere and surface simulation chamber at OU The chamber simulates Titan's atmospheric composition under a range of pressures and temperatures and through provision of external UV light and or electrical discharge can be used to form the well known Titan Aerosol species, which can subsequently be analysed using one of several analytical techniques (UV-Vis, FTIR and mass spectrometry). Simulated surfaces can be produced (icy surfaces down to 15K) and subjected to a variety of light and particles (electron and ion) sources. Chemical and physical changes in the surface may be explored using remote spectroscopy. Planetary Simulation chamber for low density atmospheres INTA-CAB The planetary simulation chamber-ultra-high vacuum equipment (PSC-UHV) has been designed to study planetary surfaces and low dense atmospheres, space environments or any other hypothetic environment at UHV. Total pressure ranges from 7 mbar (Martian conditions) to 5x10-9 mbar. A residual gas analyzer regulates gas compositions to ppm precision. Temperature ranges from 4K to 325K and most operations are computer controlled. Radiation levels are simulated using a deuterium UV lamp, and ionization sources. 5 KV electron and noble-gas discharge UV allows measurement of IR and UV spectra and chemical compositions are determined by mass spectroscopy. Planetary Simulation chamber for high density planetary atmospheres at INTA-CAB The facility allows experimental study of planetary environments under high pressure, and was designed to include underground, seafloor and dense atmosphere environments. Analytical capabilities include Raman spectra, physicochemical properties of materials, e.a. thermal conductivity. P-T can be controlled as independent variables to allow monitoring of the tolerance of microorganisms and the stability of materials and their phase changes. Planetary Simulation chamber for icy surfaces at INTA-CAB This chamber is being developed to the growth of ice samples to simulate the chemical and physical properties of ices found on both planetary bodies and their moons. The goal is to allow measurement of the physical properties of ice samples formed under planetary conditions to assess how rheolo

  13. Investigating Mount Cameroon's Magma Chamber System

    NASA Astrophysics Data System (ADS)

    Riley, S. D.; Clarke, A.; Watts, R.; Suh, C. E.

    2005-12-01

    Mount Cameroon, located in the middle of the Cameroon Volcanic Line (CVL) on the passive western margin of Cameroon, is one of Africa's most active volcanoes with seven eruptions in the past century. Many population centers are in lava flow hazard zones, making monitoring imperative. Despite its high activity level, monitoring is limited to a small network of seismometers, and only one instrument was functional immediately before the 1999 eruption. Seismic activity rose above background level only a few days prior to the eruption (Suh, et al.,2003, Bull. Volcanol., 65:267-281). In order to improve spatial coverage and potential warning time, we are designing a ground deformation monitoring network. Using existing seismic, petrologic, and historical eruption data (Ambeh,1989, PhD thesis, Leeds U., UK; Suh et al. 2003) along with corresponding models of subsurface magma storage, we apply simple elastic half-space models (Mogi, 1958; Pinel and Jaupart, 2000) to explore the nature of the volcano's plumbing system. We first assumed a closed-system and a 12km deep chamber (Ambeh, 1989), with sufficient overpressure to initiate the 1999 eruption. Given the total erupted volume of 8 x 108 m3 and the required pressure, the chamber must be ~1.2 km in diameter. Overpressure in this chamber immediately prior to eruption causes maximum surface tilt of ~0.3 microradians at 6km from the center. This small amount of deformation is not detectable by surface mounted tiltmeters, however it is detectable by borehole strainmeters. Following conduit initiation, at an average extrusion rate of 40m3 s-1 recorded for the 1999 eruption (Suh et al., 2003) and assuming a 10m radius conduit, magma would erupt roughly one full day after conduit initiation. However, if the system fills a shallow chamber at ~3km depth prior to eruption, as is the case in Hawaiian volcanoes (Dvorak & Okamura, 1987), then maximum surface tilt of ~17 microradians occurs at 1.5km from the center, making eruption prediction with tiltmeters feasible. At a 40m3 s-1 chamber filling rate, the shallow chamber would take nearly a month to reach an eruptible pressure, providing two weeks of warning with tiltmeters.

  14. The U.S. Lab is placed in vacuum chamber for leak test

    NASA Technical Reports Server (NTRS)

    2000-01-01

    With the lid of the three-story vacuum chamber in place, a worker on top checks release of the cables. Inside the chamber is the U.S. Lab, a component of the International Space Station. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  15. Proposal of a growth chamber for growing Super-Dwarf Rice in Space Agriculture

    NASA Astrophysics Data System (ADS)

    Hirai, Hiroaki; Kitaya, Yoshiaki; Tsukamoto, Koya; Yamashita, Youichirou; Hirai, Takehiro

    Space agriculture needs to be considered to supply food for space crew who stay in space over an extended time period. So far crops such as wheat, onion, oat, pea and lettuce grew to explore the possibility of space agriculture. Although rice is a staple food for most of the world, research on rice cultivation in space has not been done much. Rice grains are nutrient-rich with carbohydrate, protein and dietary fiber. Moreover, rice is a high yield crop and harvested grains have a long shelf life. However, the plant height of standard rice cultivars is relatively long, requiring much space. In addition, rice plants require higher light intensities for greater yield. For these reasons, it is difficult to establish facilities for rice culture in a limited space with a low cost. We propose to employee a super-dwarf cultivar and a small growth chamber with a new type of LEDs. The super-dwarf rice is a short-grain japonica variety and the plant height is approximately 20 cm that is one-fifth as tall as standard cultivars. The LED light used as a light source for this study can provide full spectrum of 380 nm to 750 nm. Air temperature and humidity were controlled by a Peltier device equipped in the chamber. The characteristics of the new type of LEDs and other equipments of the chamber and the ground based performance of super-dwarf rice plants grown in the chamber will be reported.

  16. Stormwater treatment at critical areas: The multi-chambered treatment train (MCTT). Final report

    SciTech Connect

    Pitt, R.; Peterson, B.; Barron, P.; Ayyoubi, A.; Clark, S.

    1999-02-01

    Past studies have identified urban runoff as a major contributor to the degradation of many urban streams and rivers. The objective of this research was to characterize typical toxicant concentrations in stormwater, and investigate the effectiveness of treatment processes to control the toxicants. A prototype treatment device (the multi-chambered treatment train, or MCTT) was tested during the final phase of this project. The MCTT is an underground device that has three main chambers: an initial grit chamber for trapping of the largest sediment and release of most volatile materials; a main setting chamber (providing initial aeration and sorbent pillows) for the trapping of fine sediment and associated toxicants and floating hydrocarbons; and a sand and peat mixed media filter (sorption-ion exchange) unit for the monitoring period. During monitoring of 13 storms at a parking facility, the pilot-scale MCTT was found to have the following overall median reduction rates: 96% for total toxicity, 98% for filtered toxicity, 83% for SS, 60% for COD, 40% for turbidity, 100% for lead, 91% for zinc, 100% for n-Nitro-di-n-proplamine, 100% for pyrene, and 99% for bis (2-ethyl-hexyl) phthalate. the color was increased by about 50% due to staining from the peat and the pH decreased by about one-half pH unit, also from the peat media. Ammonia nitrogen was increased by several times, and nitrate nitrogen had low reductions (about 14%).

  17. ORNL irradiation creep facility

    SciTech Connect

    Reiley, T.C.; Auble, R.L.; Beckers, R.M.; Bloom, E.E.; Duncan, M.G.; Saltmarsh, M.J.; Shannon, R.H.

    1980-09-01

    A machine was developed at ORNL to measure the rates of elongation observed under irradiation in stressed materials. The source of radiation is a beam of 60 MeV alpha particles from the Oak Ridge Isochronous Cyclotron (ORIC). This choice allows experiments to be performed which simulate the effects of fast neutrons. A brief review of irradiation creep and experimental constraints associated with each measurement technique is given. Factors are presented which lead to the experimental choices made for the Irradiation Creep Facility (ICF). The ICF consists of a helium-filled chamber which houses a high-precision mechanical testing device. The specimen to be tested must be thermally stabilized with respect to the temperature fluctuations imposed by the particle beam which passes through the specimen. Electrical resistance of the specimen is the temperature control parameter chosen. Very high precision in length measurement and temperature control are required to detect the small elongation rates relevant to irradiation creep in the test periods available (approx. 1 day). The apparatus components and features required for the above are presented in some detail, along with the experimental procedures. The damage processes associated with light ions are discussed and displacement rates are calculated. Recent irradiation creep results are given, demonstrating the suitability of the apparatus for high resolution experiments. Also discussed is the suitability of the ICF for making high precision thermal creep measurements.

  18. DESIGN, CONSTRUCTION, AND EVALUATION OF A CHAMBER FOR AEROBIOLOGY

    EPA Science Inventory

    A chamber was designed and constructed for aeromicrobiology applications. An ultraviolet (UV) radiation source was incorporated to sterilize the chamber between trials. Twelve bacterial species originally isolated from air samples and obtained from the American Type Culture Colle...

  19. 30 CFR 56.7807 - Flushing the combustion chamber.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has been sitting unoperated in a drill hole shall be flushed with a suitable solvent after the stem is pulled...

  20. Safety shield for vacuum/pressure-chamber windows

    NASA Technical Reports Server (NTRS)

    Shimansky, R. A.; Spencer, R.

    1980-01-01

    Optically-clear shatter-resistant safety shield protects workers from implosion and explosion of vacuum and pressure windows. Plastic shield is inexpensive and may be added to vacuum chambers, pressure chambers, and gas-filling systems.

  1. Utilizing Chamber Data for Developing and Validating Climate Change Models

    NASA Technical Reports Server (NTRS)

    Monje, Oscar

    2012-01-01

    Controlled environment chambers (e.g. growth chambers, SPAR chambers, or open-top chambers) are useful for measuring plant ecosystem responses to climatic variables and CO2 that affect plant water relations. However, data from chambers was found to overestimate responses of C fluxes to CO2 enrichment. Chamber data may be confounded by numerous artifacts (e.g. sidelighting, edge effects, increased temperature and VPD, etc) and this limits what can be measured accurately. Chambers can be used to measure canopy level energy balance under controlled conditions and plant transpiration responses to CO2 concentration can be elucidated. However, these measurements cannot be used directly in model development or validation. The response of stomatal conductance to CO2 will be the same as in the field, but the measured response must be recalculated in such a manner to account for differences in aerodynamic conductance, temperature and VPD between the chamber and the field.

  2. An Experimental Study of Upward Burning Over Long Solid Fuels: Facility Development and Comparison

    NASA Technical Reports Server (NTRS)

    Kleinhenz, Julie; Yuan, Zeng-Guang

    2011-01-01

    As NASA's mission evolves, new spacecraft and habitat environments necessitate expanded study of materials flammability. Most of the upward burning tests to date, including the NASA standard material screening method NASA-STD-6001, have been conducted in small chambers where the flame often terminates before a steady state flame is established. In real environments, the same limitations may not be present. The use of long fuel samples would allow the flames to proceed in an unhindered manner. In order to explore sample size and chamber size effects, two large chambers were developed at NASA GRC under the Flame Prevention, Detection and Suppression (FPDS) project. The first was an existing vacuum facility, VF-13, located at NASA John Glenn Research Center. This 6350 liter chamber could accommodate fuels sample lengths up to 2 m. However, operational costs and restricted accessibility limited the test program, so a second laboratory scale facility was developed in parallel. By stacking additional two chambers on top of an existing combustion chamber facility, this 81 liter Stacked-chamber facility could accommodate a 1.5 m sample length. The larger volume, more ideal environment of VF-13 was used to obtain baseline data for comparison with the stacked chamber facility. In this way, the stacked chamber facility was intended for long term testing, with VF-13 as the proving ground. Four different solid fuels (adding machine paper, poster paper, PMMA plates, and Nomex fabric) were tested with fuel sample lengths up to 2 m. For thin samples (papers) with widths up to 5 cm, the flame reached a steady state length, which demonstrates that flame length may be stabilized even when the edge effects are reduced. For the thick PMMA plates, flames reached lengths up to 70 cm but were highly energetic and restricted by oxygen depletion. Tests with the Nomex fabric confirmed that the cyclic flame phenomena, observed in small facility tests, continued over longer sample. New features were also observed at the higher oxygen/pressure conditions available in the large chamber. Comparison of flame behavior between the two facilities under identical conditions revealed disparities, both qualitative and quantitative. This suggests that, in certain ranges of controlling parameters, chamber size and shape could be one of the parameters that affect the material flammability. If this proves to be true, it may limit the applicability of existing flammability data.

  3. Combustion interaction with radiation-cooled chambers

    NASA Technical Reports Server (NTRS)

    Rosenberg, S. D.; Jassowski, D. M.; Barlow, R.; Lucht, R.; Mccarty, K.

    1990-01-01

    Over 15 hours of thruster operation at temperatures between 1916 and 2246 C without failure or erosion has been demonstrated using iridium-coated rhenium chamber materials with nitrogen tetroxide/monomethylhydrazine propellants operating over a mixture ratio range of 1.60-2.05. Research is now under way to provide a basic understanding of the mechanisms which make high-temperature operation possible and to extend the capability to a wider range of conditions, including other propellant combinations and chamber materials. Techniques have been demonstrated for studying surface fracture phenomena. These include surface Raman and Auger for study of oxide formation, surface Raman and X-ray diffraction to determine the oxide phase, Auger to study oxide stoichiometry, and sputter Auger to study interdiffusion of alloy species.

  4. Space station auxiliary thrust chamber technology

    NASA Technical Reports Server (NTRS)

    Senneff, J. M.

    1987-01-01

    A program to design, fabricate, and test a 50 lb sub f (222 N) thruster was undertaken to demonstrate the applicability of the reverse flow concept as an item of auxillary propulsion for the Space Station. The thruster was to operate at a mixture ratio (O/F) of 4, be capable of operating for 2 million lb sub f-seconds (8.896 million N-seconds) impulse with a chamber pressure of 75 psia (52N/sq cm) and a nozzle area ratio of 40. A successful demonstration of an (0/F) of 4 thruster, was followed by the design objective of operating at (O/F) of 8. The demonstration of this thruster resulted in the order of and additional (O/F) of 8 thruster chamber under the present NAS 3-24883 contract. The effort to fabricate and test the second (0/F) of 8 thruster is documented.

  5. Gas Injection Apparatus for Vacuum Chamber

    SciTech Connect

    Almabouada, F.; Louhibi, D.; Hamici, M. [Centre de Developpement des Technologies Avancees CDTA, Division Milieux Ionises and Laser, BP 17, Cite du 20 Aout 1956, Baba Hassen, Alger (Algeria)

    2011-12-26

    We present in this article a gas injection apparatus which comprises the gas injector and its electronic command for vacuum chamber applications. Some of these applications are thin-film deposition by a pulsed laser deposition (PLD) or a cathodic arc deposition (arc-PVD) and the plasma generation. The electronic part has been developed to adjust the flow of the gas inside the vacuum chamber by controlling both of the injector's opening time and the repetition frequency to allow a better gas flow. In this case, the system works either on a pulsed mode or a continuous mode for some applications. In addition, the repetition frequency can be synchronised with a pulsed laser by an external signal coming from the laser, which is considered as an advantage for users. Good results have been obtained using the apparatus and testing with Argon and Nitrogen gases.

  6. Wiring the new COMPASS Drift Chamber

    NASA Astrophysics Data System (ADS)

    Medlock, Lacey; Compass Dc5 Team

    2014-09-01

    COMPASS, a fixed-target experiment at CERN, will examine the first ever polarized Drell-Yan events that may illuminate how the quark angular momentum contributes to the spin of the proton. A new drift chamber must be constructed to replace an older straw chamber that is currently in use. In order to construct the drift chamber 4616 gold-plated tungsten wires are used, half are 100 micron (field wires) which provide an electrical field and half are 20 micron (sense wires) which measure position. Because of the difference in wire width, two very different stringing techniques had to be developed. The 20 micron sense wire was too fragile and thin to be handled in the same manner as the 100 micron field wire, so different tools had to be used in order to ensure the stability and efficacy of the chamber. Additionally, different soldering techniques had to be used for the two different types of wires to guarantee both that the field wires did not slip out of their solder joints during the process of stringing the sense wires and that both types of wires had smooth, even solder joints that would not require repair. This poster will detail several aspects of wire stringing, including how to string different widths of wire and how to overcome difficulties arising from using two different types of wire during the stringing process. COMPASS, a fixed-target experiment at CERN, will examine the first ever polarized Drell-Yan events that may illuminate how the quark angular momentum contributes to the spin of the proton. A new drift chamber must be constructed to replace an older straw chamber that is currently in use. In order to construct the drift chamber 4616 gold-plated tungsten wires are used, half are 100 micron (field wires) which provide an electrical field and half are 20 micron (sense wires) which measure position. Because of the difference in wire width, two very different stringing techniques had to be developed. The 20 micron sense wire was too fragile and thin to be handled in the same manner as the 100 micron field wire, so different tools had to be used in order to ensure the stability and efficacy of the chamber. Additionally, different soldering techniques had to be used for the two different types of wires to guarantee both that the field wires did not slip out of their solder joints during the process of stringing the sense wires and that both types of wires had smooth, even solder joints that would not require repair. This poster will detail several aspects of wire stringing, including how to string different widths of wire and how to overcome difficulties arising from using two different types of wire during the stringing process. This research was supported in part by the DOE under Grant Number DE-FG03-94ER40860.

  7. Fast-burn combustion chamber design for natural gas engines

    Microsoft Academic Search

    R. L. Evans; J. Blaszczyk

    1998-01-01

    The work presented in this paper compares the performance and emissions of the UBC Squish-Jet fast-burn combustion chamber with a baseline bowl-in-piston (BIP) chamber. It was found that the increased turbulence generated in the fastburn combustion chambers resulted in 5 to 10% faster burning of the air-fuel mixture compared to a conventional BIP chamber. The faster burning was particularly noticeable

  8. Nursing Facilities (Medicaid)

    MedlinePLUS

    ... provided by Medicaid or other state agencies. Where Nursing Facility Services are provided Medicaid coverage of Nursing ... the Medicaid Nursing Facility benefit. Who may receive Nursing Facility Services Nursing facility services for are required ...

  9. Decompression sickness following altitude-chamber training.

    PubMed

    Studer, Nicholas M; Hughes, John R; Puskar, Joseph

    2015-01-01

    Decompression sickness (DCS) is one of several dysbarisms (medical conditions resulting from a change in atmospheric pressure) that can be encountered by the Special Operations Forces (SOF) medical provider. DCS can present with several different manifestations. The authors present the case of a 23-year-old Airman who presented with vague neurologic symptoms following altitude-chamber training. They discuss the care of casualties with DCS and its implications for SOF. PMID:25770794

  10. High pressure hydrogen time projection chamber

    SciTech Connect

    Goulianos, K.

    1983-01-01

    We describe a high pressure hydrogen gas time projection chamber which consists of two cylindrical drift regions each 45 cm in diameter and 75 cm long. Typically, at 15 atm of H/sub 2/ with 2 kV/cm drift field and 7 kV on the 35..mu.. sense wires, the drift velocity is about 0.5 cm/..mu..sec and the spatial resolution +-200..mu...

  11. Visual-Inspection Probe For Cryogenic Chamber

    NASA Technical Reports Server (NTRS)

    Friend, Steve; Valenzuela, James; Yoshinaga, Jay

    1990-01-01

    Visual-inspection probe that resembles borescope enables observer at ambient temperature to view objects immersed in turbulent flow of liquid oxygen, liquid nitrogen, or other cryogenic fluid. Design of probe fairly conventional, except special consideration given to selection of materials and to thermal expansion to provide for expected range of operating temperatures. Penetrates wall of cryogenic chamber to provide view of interior. Similar probe illuminates scene. View displayed on video monitor.

  12. The fast Ice Nucleus chamber FINCH

    NASA Astrophysics Data System (ADS)

    Bundke, U.; Nillius, B.; Jaenicke, R.; Wetter, T.; Klein, H.; Bingemer, H.

    2008-11-01

    We present first results of our new developed Ice Nucleus (IN) counter FINCH from the sixth Cloud and Aerosol Characterization Experiment (CLACE 6) campaign at Jungfraujoch station, 3571 m asl. Measurements were made at the total and the ICE CVI inlet. Laboratory measurements of ice onset temperatures by FINCH are compared to those of the static diffusion chamber FRIDGE (FRankfurt Ice Deposition Freezing Experiment). Within the errors of both new instruments the results compare well to published data.

  13. Adherent Thermal Barrier For Combustion Chamber

    NASA Technical Reports Server (NTRS)

    Quentmeyer, Richard J.

    1989-01-01

    In improved method, fabrication begins with machining of aluminum mandrel to requisite cylindrical shape. Heat-barrier coating - yttria-stablized zirconia - plasma-sprayed on mandrel to thickness of 0.076 mm. Nickel/chromium layer about 0.025 mm thick sprayed on zirconia. Thin zirconia coating reduces maximum operating temperature of copper wall of chamber from 844 to 334 K. At lower temperature, copper liner stronger and undergoes less strain and less tendency to distort and crack.

  14. High counting rate resistive-plate chamber

    SciTech Connect

    Anderson, D.F.; Kwan, S.; Peskov, V.

    1993-08-01

    Resistive-glass, parallel-plate chambers are studied in both spark and avalanche modes. In the avalanche mode rates of over 10{sup 3}s{sup {minus}1}cm{sup {minus}2} are achievable with a total collected charges per pulse of 10{sup 8} electrons. Operated at low pressure and with secondary-electron emission from a porous CsI surface, a timing resolution of 600 ps has been measured. Future improvements are discussed.

  15. Detector Physics of Resistive Plate Chambers

    Microsoft Academic Search

    Christian Lippmann; R Stock; W Riegler

    2003-01-01

    Resistive Plate Chambers (RPCs) are gaseous parallel plate avalanche detectors that implement electrodes made from a material with a high volume resistivity between 10^7 and 10^12 Ohm cm. Large area RPCs with 2mm single gaps operated in avalanche mode provide above 98% efficiency and a time resolution of around 1ns up to a flux of several kHz\\/cm2. These Trigger RPCs

  16. CFD Code Survey for Thrust Chamber Application

    NASA Technical Reports Server (NTRS)

    Gross, Klaus W.

    1990-01-01

    In the quest fo find analytical reference codes, responses from a questionnaire are presented which portray the current computational fluid dynamics (CFD) program status and capability at various organizations, characterizing liquid rocket thrust chamber flow fields. Sample cases are identified to examine the ability, operational condition, and accuracy of the codes. To select the best suited programs for accelerated improvements, evaluation criteria are being proposed.

  17. Image digitizer system for bubble chamber laser

    SciTech Connect

    Haggerty, H

    1986-12-08

    An IBM PC-based image digitizer system has been assembled to monitor the laser flash used for holography at the 15 foot bubble chamber. The hardware and the operating software are outlined. For an operational test of the system, an array of LEDs was flashed with a 10 microsecond pulse and the image was grabbed by one of the operating programs and processed. (LEW)

  18. A pro/con review comparing the use of mono- and multiplace hyperbaric chambers for critical care.

    PubMed

    Lind, Folke

    2015-03-01

    Hyperbaric oxygen treatment (HBOT) of critically ill patients requires special technology and appropriately trained medical team staffing for '24/7' emergency services. Regardless of the chamber system used it is essential that the attending nurse and critical care specialist understand the physics and physiology of hyperbaric oxygen for safe treatment and compression/decompression procedures. Mechanical ventilation through endotracheal tube or tracheotomy is hampered by the increased gas density and flow resistance with risks of hypoventilation, carbon dioxide retention and oxygen seizures. Ventilation should be controlled and arterial and end-tidal carbon dioxide levels monitored. Haemodynamically unstable patients require careful risk-benefit evaluation, invasive monitoring and close supervision of inotropes, vasopressors and sedative drug infusions to avoid blood pressure swings and risk of awareness. Two distinctly different chambers are used for critical care. Small cost-efficient and easy-to-install acrylic monoplace chambers require less staffing and no inside attendant. Major disadvantages include patient isolation with difficulties to maintain standard organ support and invasive monitoring. Monoplace ventilators are less advanced and require the use of muscle relaxants and excessive sedation. Intravenous lines must be changed to specially designed IV pumps located outside the chamber with chamber pass-through and risk of inaccurate drug delivery. The multiplace chamber is better suited for HBOT of critically ill patients with failing vital functions and organ systems, primarily because it permits appropriate ICU equipment to be used inside the chamber by accompanying staff. Normal 'hands-on' intensive care continues during HBOT with close attention to all aspects of critical patient care. A regional trauma hospital-based rectangular chamber system immediately bordering critical care and emergency ward facilities is the best solution for safe HBOT in the critically ill. Disadvantages include long-term commitment, larger space requirements and higher capitalization, technical and staffing costs. PMID:25964041

  19. U.S. Chamber of Commerce

    NSDL National Science Digital Library

    One would be hard pressed to find a better slogan for the U.S. Chamber of Commerce than â??Fighting for Your Businessâ?, so it is rather fortunate that they have already effectively trademarked these exact words. With a long and storied history dating back to 1912, the U.S Chamber of Commerce is the worldâ??s largest not-for-profit business federation, representing over 3 million businesses and 2800 state and local chambers. Their website will be most useful to both businesspersons and those with an interest in the role this organization plays throughout the United States in terms of its effect on the creation of national and local policy regarding the climate for small and large businesses. As might be expected, the homepage contains a full-site directory, which will lead visitors to information on international trade, current issues of relevance to business, and the Chamberâ??s own Center for Workforce Preparation. Some visitors may also wish to sign up for their free weekly e-newsletters, which cover topics such as corporate citizenship and workforce preparation.

  20. 30 CFR 57.11054 - Communication with refuge chambers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Communication with refuge chambers. 57.11054 Section 57...Only § 57.11054 Communication with refuge chambers. Telephone or other voice...shall be provided between the surface and refuge chambers and such systems shall be...

  1. 30 CFR 57.11054 - Communication with refuge chambers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Communication with refuge chambers. 57.11054 Section 57...Only § 57.11054 Communication with refuge chambers. Telephone or other voice...shall be provided between the surface and refuge chambers and such systems shall be...

  2. 30 CFR 57.11054 - Communication with refuge chambers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Communication with refuge chambers. 57.11054 Section 57...Only § 57.11054 Communication with refuge chambers. Telephone or other voice...shall be provided between the surface and refuge chambers and such systems shall be...

  3. 30 CFR 57.11054 - Communication with refuge chambers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Communication with refuge chambers. 57.11054 Section 57...Only § 57.11054 Communication with refuge chambers. Telephone or other voice...shall be provided between the surface and refuge chambers and such systems shall be...

  4. Combustion chamber system for kerosine internal combustion engine

    Microsoft Academic Search

    S. Yagi; J. Ootani; M. Araki; F. Yoshida

    1986-01-01

    A combustion chamber system is described for an overhead valve type kerosine internal combustion engine, comprising: a cylinder head; a piston slidable in a cylinder; a main combustion chamber defined by a lower surface of a cylinder head and an upper surface of the piston; an auxiliary combustion chamber defined within the cylinder head and spaced from the main combustion

  5. STATUS OF COLDDIAG: A COLD VACUUM CHAMBER FOR DIAGNOSTICS

    E-print Network

    Istituto Nazionale di Fisica Nucleare (INFN)

    of the vacuum chamber, induce non- thermal outgassing from the cryogenic surface and heat the undulator. FigureSTATUS OF COLDDIAG: A COLD VACUUM CHAMBER FOR DIAGNOSTICS S. Gerstl*, T. Baumbach, S. Casalbuoni, A chamber for diagnostics is under construction. The following diagnostics will be implemented: i) retarding

  6. Flow characteristics of the dynamic "EPA flux chamber"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A dynamic flux chamber, commonly referred as the “EPA chamber”, is one method that has been adapted to investigate spatial gas emission on feedlot surfaces. However, the flow characteristics within the chamber have not been evaluated to determine if it can be effectively used outside of its origina...

  7. Exciting Internship at the American Arab Chamber of Commerce

    E-print Network

    Cinabro, David

    Exciting Internship at the American Arab Chamber of Commerce Take advantage of the opportunity to intern at the largest Arab American business organization in the country. The Chamber builds economic. The Chamber organizes many exciting events, such as the Annual Golf Open, the Annual Arab International

  8. Internal combustion engine with auxiliary chamber having variable size openings

    Microsoft Academic Search

    S. Yagi; K. Inoue

    1975-01-01

    A three-valve spark-ignition internal combustion piston engine has an auxiliary combustion chamber connected to each main combustion chamber through a torch nozzle. The intake valve for the auxiliary chamber is provided with a skirt for varying the effective size of the torch nozzle under controlled turning movement of the intake valve stem. The effective size of a restricted opening which

  9. 30 CFR 56.7807 - Flushing the combustion chamber.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Flushing the combustion chamber. 56.7807 Section 56.7807 ...Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has been...

  10. 30 CFR 56.7807 - Flushing the combustion chamber.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Flushing the combustion chamber. 56.7807 Section 56.7807 ...Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has been...

  11. 30 CFR 57.7807 - Flushing the combustion chamber.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Flushing the combustion chamber. 57.7807 Section 57.7807 ...Piercing-Surface Only § 57.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has been...

  12. 30 CFR 56.7807 - Flushing the combustion chamber.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Flushing the combustion chamber. 56.7807 Section 56.7807 ...Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has been...

  13. 30 CFR 56.7807 - Flushing the combustion chamber.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Flushing the combustion chamber. 56.7807 Section 56.7807 ...Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has been...

  14. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Agriculture 3 2011-01-01 2011-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture...and Grading Service 1 Equipment and Utensils § 58.423 Cheese vacuumizing chamber. The vacuum chamber shall be...

  15. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agriculture 3 2010-01-01 2010-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture...and Grading Service 1 Equipment and Utensils § 58.423 Cheese vacuumizing chamber. The vacuum chamber shall be...

  16. Plant growth chamber based on space proven controlled environment technology

    Microsoft Academic Search

    Ronald W. Ignatius; Matt H. Ignatius; Henry J. Imberti

    1997-01-01

    Quantum Devices, Inc., in conjunction with Percival Scientific, Inc., and the Wisconsin Center for Space Automation and Robotics (WCSAR) have developed a controlled environment plant growth chamber for terrestrial agricultural and scientific applications. This chamber incorporates controlled environment technology used in the WCSAR ASTROCULTURE™ flight unit for conducting plant research on the Space Shuttle. The new chamber, termed CERES 2010,

  17. An optical imaging system for window chambers in MRI system

    Microsoft Academic Search

    Yuxiang Lin; Mir F. S. Salek; Nicki Jennings; Arthur F. Gmitro

    2008-01-01

    Window chambers are support structures implanted in the dorsal skin fold of a rodent model. Optical imaging of window chambers has been used in many basic cancer and vascular biology studies. We have recently shown that this technique can be extended to MRI by using plastic rather than metal window chambers. Here we describe a system for simultaneous optical and

  18. Engineering analyses of large precision cathode strip chambers for GEM

    SciTech Connect

    Horvath, J.A.; Belser, F.C.; Pratuch, S.M.; Wuest, C.R. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States); Mitselmakher, G. [Superconducting Super Collider Lab., Dallas, TX (United States)] [Superconducting Super Collider Lab., Dallas, TX (United States); Gordeev, A. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)] [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Johnson, C.V. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States); [Superconducting Super Collider Lab., Dallas, TX (United States); Polychronakos, V.A. [Brookhaven National Lab., Upton, NY (United States)] [Brookhaven National Lab., Upton, NY (United States); Golutvin, I.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation)] [Joint Institute for Nuclear Research, Dubna (Russian Federation)

    1993-10-21

    Structural analyses of large precision cathode strip chambers performed up to the date of this publication are documented. Mechanical property data for typical chamber materials are included. This information, originally intended to be an appendix to the {open_quotes}CSC Structural Design Bible,{close_quotes} is presented as a guide for future designers of large chambers.

  19. Mini-strip ionization chamber for ?-ray imaging

    Microsoft Academic Search

    V. Solovov; V. Chepel; M. I. Lopes; J. Abrantes; R. Ferreira Marques; A. J. P. L. Policarpo

    2003-01-01

    We are developing a liquid xenon ionization chamber for single-photon radioisotope imaging in nuclear medicine. The chamber has a mini-strip plate made of glass substrate with metal strips deposited along two perpendicular directions. Here, we report on a version of this chamber with an additional grid, improved trigger capability and the development of the multichannel readout system based on highly

  20. Uniformity of soil-plant-atmosphere-research chambers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Uniformity of plant responses and gas exchange calculations within and among Soil-Plant-Atmosphere-Research (SPAR) chambers was evaluated using 12 SPAR chambers located at Beltsville, MD. Periodic non-destructive and destructive measurements were conducted at the same locations within each chamber ...

  1. Photochemical Method of Maintaining a Continuous Cloud Chamber

    Microsoft Academic Search

    Richard E. Vollrath

    1952-01-01

    tration of HCl throughout the volume of the chamber. When the source of the HCl vapor which is to condense with water vapor on ions is a solution of HCl there will be a concentration gradient of HCl vapor in the chamber. The concentration may be high enough at the upper part of the chamber to produce ion tracks. But

  2. MEASUREMENT OF SOIL RESPIRATION IN SITU: CHAMBER TECHNIQUES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chambers temporarily sealed to the soil surface are important and often the only means of measuring trace gas emissions to the atmosphere. However, such chamber measurements are not exempt from methodological problems. This review article identifies known sources of chamber-induced errors encounte...

  3. Experience in construction and testing of plastic limited streamer chambers

    Microsoft Academic Search

    A. H. Ball; R. L. Bard; D. Bensen; C. Cates; J. D. Colmer; P. Floros; D. J. Fritz; P. R. Goldey; W. W. Miller; D. T. Norkin; P. Rapp; P. Rozmarynowski; J. R. Lee; M. San Sebastian; J. Schultz; A. Skuja; R. W. Springer; J. Subramanyam; T. Zawistowski; G. T. Zorn

    1990-01-01

    The manufacture and testing of multicell limited streamer chambers for use in the hadron calorimeter of the OPAL detector and LEP (Large Electron Positron Collider) are described. All operations, from chamber cathode coating to the testing of completed subassemblies, have been performed under the same roof. With reasonable care and quality control, the established technology produced chambers several meters long

  4. Design and performance of future KrF laser-fusion facilities

    Microsoft Academic Search

    D. B. Harris; J. A. Sullivan; S. V. Coggeshall

    1989-01-01

    The US inertial confinement fusion program is investigating the feasibility of constructing a high-gain laboratory microfusion facility (LMF). Considerable uncertainties and risks exist for all the driver candidates in proceeding directly to this facility without an intermediate step. The risks fall into the categories of driver performance and cost, target physics, and target chamber performance. Los Alamos has developed a

  5. RIF Final Report: Experimental Facility Design for an Integrated Space Technology Research

    E-print Network

    Zhou, Chongwu

    CHAFF-IV facility required significant control, measurement, and automation to prevent system damage1 RIF Final Report: Experimental Facility Design for an Integrated Space Technology Research Laboratory at USC Joseph Wang, Phil Muntz, Dan Erwin A. Background and Objectives A vacuum chamber system

  6. Implementation of a near backscattering imaging system on the National Ignition Facility

    Microsoft Academic Search

    A. J. MacKinnon; T. McCarville; K. Piston; C. Niemann; G. Jones; I. Reinbachs; R. Costa; J. Celeste; G. Holtmeier; R. Griffith; R. Kirkwood; B. MacGowan; S. H. Glenzer; M. R. Latta

    2004-01-01

    A near backscattering imaging diagnostic system is being implemented on the first quad of beams on the National Ignition Facility. This diagnostic images diffusing scatter plates, placed around the final focus lenses on the National Ignition Facility target chamber, to quantitatively measure the fraction of light backscattered outside of the focusing cone angle of incident laser beam. A wide-angle imaging

  7. A European Mars Simulation Wind Tunnel Facility

    NASA Astrophysics Data System (ADS)

    Merrison, J. P.; Gunnlaugsson, H. P.; Knak-Jensen, S.; Per, N.

    2010-12-01

    We present details of a recently completed European simulation wind tunnel facility which is capable of re-creating the environmental conditions at the surface of Mars, this new addition complements several other large scale simulation facilities at Aarhus University in Denmark. It will be used for the multi-disciplinary scientific study of aerosol formation and transport (on Mars and earth), granular electrification, magnetic properties, erosion, cohesion/adhesion, water transport, UV induced mineralogy, bacterial survival and many others. It will be accessible to international collaborators and space agencies for instrument testing, calibration and qualification. It has been financed by the European space agency (ESA) as well as the Aarhus University Science Faculty and the Villum Kahn Rasmussen fund. The facility consists of a 50m3 environmental chamber capable of low pressure operation (0.02-1000mbar) and cryogenic temperatures (-130°C up to +60°C). This chamber houses a re-circulating wind tunnel able to generate wind speeds up to 25m/s and an automated dust injection system has been developed to produce suspended particulates (aerosols). It employs a unique LED based optical illumination system (solar simulator) and an advanced network based control system. Laser based optoelectronic instrumentation is used to quantify and monitor dust suspension and deposition. This involves a commercial Laser Doppler Anemometer and specially developed instrument prototypes constructed at Aarhus University. Photograph of the new (European) Environmental Wind Tunnel Facility.

  8. Design of a sample chamber for spatial emissivity measurements using thermal imaging

    NASA Astrophysics Data System (ADS)

    Clarke, F. J. J.; Boyd, N. A.; Leonard, J. K.

    1988-01-01

    Optical and electronic modifications have been made to a TICM II thermal imager to allow its use in near-focus radiometric measurements. A GEMS image processing system has customized enhancements to the existing GEMMA software permitting pixel-by-pixel restoration and radiometric calibration of images with user-defined algorithms. To allow emissivity measurements to be made at near-ambient temperatures, a nonreflecting cryogenic sample chamber is necessary to remove the reflected component of sample radiance. The design and construction of such a sample chamber are discussed in detail in relation to the NPL facility nearing completion for measuring the emissivity of nonuniform materials or objects. Particular features are the avoidance of vacuum systems for purging or insulation, and the geometrical and thermal design to give easy of handling and a long operating period from a single filling with liquid nitrogen.

  9. Extreme high-rate capable timing resistive plate chambers with ceramic electrodes

    NASA Astrophysics Data System (ADS)

    Laso Garcia, A.; Kaspar, M.; Kämpfer, B.; Kotte, R.; Naumann, L.; Peschke, R.; Stach, D.; Wendisch, C.; Wüstenfeld, J.

    2012-10-01

    The future Compressed Baryonic Matter experiment to be built at the Facility for Antiproton and Ion Research in Darmstadt, Germany, will create the highest particle densities ever created in a laboratory. One of its components, the Time-of-Flight Wall, will be comprised of Resistive Plate Chambers. The high particle fluxes expected at the most inner region, close to the beam pipe, have led to the research of new low-resistive materials to be used as electrodes. Si3N4/SiC composites are a very good candidate for this function. Their bulk resistivity, in the order of 109-1010 ? cm, allows for increased rate capabilities up to 106 s-1 cm-2. In this report, the properties of these new materials will be discussed. Also, the performance of resistive plate chambers with ceramic electrodes under irradiation in electron and proton beams will be presented.

  10. Recent Improvements to the Acoustical Testing Laboratory at the NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Podboy, Devin M.; Mirecki, Julius H.; Walker, Bruce E.; Sutliff, Daniel L.

    2014-01-01

    The Acoustical Testing Laboratory (ATL) consists of a 27- by 23- by 20-ft (height) convertible hemi/anechoic chamber and separate sound-attenuating test support enclosure. Absorptive fiberglass wedges in the test chamber provide an anechoic environment down to 100 Hz. A spring-isolated floor system affords vibration isolation above 3 Hz. These specifications, along with very low design background levels, enable the acquisition of accurate and repeatable acoustical measurements on test articles that produce very low sound pressures. Removable floor wedges allow the test chamber to operate in either a hemi-anechoic or anechoic configuration, depending on the size of the test article and the specific test being conducted. The test support enclosure functions as a control room during normal operations. Recently improvements were accomplished in support of continued usage of the ATL by NASA programs including an analysis of the ultra-sonic characteristics. A 3-D traverse system inside the chamber was utilized for acquiring acoustic data for these tests. The traverse system drives a linear array of 13, 1/4 in.-microphones spaced 3 in. apart (36 in. span). An updated data acquisition system was also incorporated into the facility.

  11. High counting rate resistive-plate chamber

    SciTech Connect

    Peskov, V.; Anderson, D.F.; Kwan, S.

    1993-05-01

    Parallel-plate avalanche chambers (PPAC) are widely used in physics experiments because they are fast (<1 ns) and have very simple construction: just two parallel metallic plates or mesh electrodes. Depending on the applied voltage they may work either in spark mode or avalanche mode. The advantage of the spark mode of operation is a large signal amplitude from the chamber, the disadvantage is that there is a large dead time (msec) for the entire chamber after an event. The main advantage of the avalanche mode is high rate capability 10{sup 5} counts/mm{sup 2}. A resistive-plate chamber (RPC) is similar to the PPAC in construction except that one or both of the electrodes are made from high resistivity ({ge}10{sup 10} {Omega}{center_dot}cm) materials. In practice RPCs are usually used in the spark mode. Resistive electrodes are charged by sparks, locally reducing the actual electric field in the gap. The size of the charged surface is about 10 mm{sup 2}, leaving the rest of the detector unaffected. Therefore, the rate capability of such detectors in the spark mode is considerably higher than conventional spark counters. Among the different glasses tested the best results were obtained with electron type conductive glasses, which obey Ohm`s law. Most of the work with such glasses was done with high pressure parallel-plate chambers (10 atm) for time-of-flight measurements. Resistive glasses have been expensive and produced only in small quantities. Now resistive glasses are commercially available, although they are still expensive in small scale production. From the positive experience of different groups working with the resistive glasses, it was decided to review the old idea to use this glass for the RPC. This work has investigated the possibility of using the RPC at 1 atm and in the avalanche mode. This has several advantages: simplicity of construction, high rate capability, low voltage operation, and the ability to work with non-flammable gases.

  12. Herds of methane chambers grazing bubbles

    NASA Astrophysics Data System (ADS)

    Grinham, Alistair; Dunbabin, Matthew

    2014-05-01

    Water to air methane emissions from freshwater reservoirs can be dominated by sediment bubbling (ebullitive) events. Previous work to quantify methane bubbling from a number of Australian sub-tropical reservoirs has shown that this can contribute as much as 95% of total emissions. These bubbling events are controlled by a variety of different factors including water depth, surface and internal waves, wind seiching, atmospheric pressure changes and water levels changes. Key to quantifying the magnitude of this emission pathway is estimating both the bubbling rate as well as the areal extent of bubbling. Both bubbling rate and areal extent are seldom constant and require persistent monitoring over extended time periods before true estimates can be generated. In this paper we present a novel system for persistent monitoring of both bubbling rate and areal extent using multiple robotic surface chambers and adaptive sampling (grazing) algorithms to automate the quantification process. Individual chambers are self-propelled and guided and communicate between each other without the need for supervised control. They can maintain station at a sampling site for a desired incubation period and continuously monitor, record and report fluxes during the incubation. To exploit the methane sensor detection capabilities, the chamber can be automatically lowered to decrease the head-space and increase concentration. The grazing algorithms assign a hierarchical order to chambers within a preselected zone. Chambers then converge on the individual recording the highest 15 minute bubbling rate. Individuals maintain a specified distance apart from each other during each sampling period before all individuals are then required to move to different locations based on a sampling algorithm (systematic or adaptive) exploiting prior measurements. This system has been field tested on a large-scale subtropical reservoir, Little Nerang Dam, and over monthly timescales. Using this technique, localised bubbling zones on the water storage were found to produce over 50,000 mg m-2 d-1 and the areal extent ranged from 1.8 to 7% of the total reservoir area. The drivers behind these changes as well as lessons learnt from the system implementation are presented. This system exploits relatively cheap materials, sensing and computing and can be applied to a wide variety of aquatic and terrestrial systems.

  13. High counting rate resistive-plate chamber

    SciTech Connect

    Peskov, V.; Anderson, D.F.; Kwan, S.

    1993-05-01

    Parallel-plate avalanche chambers (PPAC) are widely used in physics experiments because they are fast (<1 ns) and have very simple construction: just two parallel metallic plates or mesh electrodes. Depending on the applied voltage they may work either in spark mode or avalanche mode. The advantage of the spark mode of operation is a large signal amplitude from the chamber, the disadvantage is that there is a large dead time (msec) for the entire chamber after an event. The main advantage of the avalanche mode is high rate capability 10[sup 5] counts/mm[sup 2]. A resistive-plate chamber (RPC) is similar to the PPAC in construction except that one or both of the electrodes are made from high resistivity ([ge]10[sup 10] [Omega][center dot]cm) materials. In practice RPCs are usually used in the spark mode. Resistive electrodes are charged by sparks, locally reducing the actual electric field in the gap. The size of the charged surface is about 10 mm[sup 2], leaving the rest of the detector unaffected. Therefore, the rate capability of such detectors in the spark mode is considerably higher than conventional spark counters. Among the different glasses tested the best results were obtained with electron type conductive glasses, which obey Ohm's law. Most of the work with such glasses was done with high pressure parallel-plate chambers (10 atm) for time-of-flight measurements. Resistive glasses have been expensive and produced only in small quantities. Now resistive glasses are commercially available, although they are still expensive in small scale production. From the positive experience of different groups working with the resistive glasses, it was decided to review the old idea to use this glass for the RPC. This work has investigated the possibility of using the RPC at 1 atm and in the avalanche mode. This has several advantages: simplicity of construction, high rate capability, low voltage operation, and the ability to work with non-flammable gases.

  14. Replenishment of magma chambers by light inputs

    NASA Astrophysics Data System (ADS)

    Huppert, Herbert E.; Sparks, R. Stephen J.; Whitehead, John A.; Hallworth, Mark A.

    1986-05-01

    Magma chambers, particularly those of basaltic composition, are often replenished by an influx of magma whose density is less than that of the resident magma. This paper describes the fundamental fluid mechanics involved in the replenishment by light inputs. If ? denotes the uniform density of the resident magma and ? — ?? that of the input, the situation is described by the reduced gravity g' = g??/?, the volume flux Q, and the viscosities of the resident and input magmas ?e and ?i, respectively. The (nondimensional) Reynolds numbers, Ree = (g'Q3)1/5/?e and Rei = (g'Q3)1/5/?i and chamber geometry then completely specify the system. For sufficiently low values of the two Reynolds numbers (each less than approximately 10), the input rises as a laminar conduit. For larger values of the Reynolds numbers, the conduit may break down and exhibit either a varicose or a meander instability and entrain some resident magma. At still larger Reynolds numbers, the flow will become quite unsteady and finally turbulent. The values of the Reynolds numbers at which these transitions occur have been documented by a series of experiments with water, glycerine, and corn syrup. If the input rises as a turbulent plume, significant entrainment of the resident magma can take place. The final spatial distribution of the mixed magma depends on the geometry of the chamber. If the chamber is much wider than it is high, the mixed magma forms a compositionally stratified region between the roof and a sharp front above uncontaminated magma. In the other geometrical extreme, the input magma is mixed with almost all of the resident magma. If the density of the resident magma is already stratified, the input plume may penetrate only part way into the chamber, even though its initial density is less than that of the lowest density resident magma. The plume will then intrude horizontally and form a hybrid layer at an intermediate depth. This provides a mechanism for preventing even primitive basaltic magmas of minimum density from erupting at the surface. By conducting an experiment using aqueous solutions, we show that entrainment can lead to crystallization of the magma in the input plume by making it locally supersaturated. All these effects are discussed and illustrated by photographs of laboratory experiments.

  15. The Allosphere: A Large-Scale Immersive Surround-View Instrument Tobias Hollerer, holl@cs.ucsb.edu

    E-print Network

    Hollerer, Tobias

    inner sur- faces), making it one of the largest quasi-anechoic rooms in the world. Standing inside. The three-story high cubical space comprises an anechoic chamber with a spherical display screen, ten meters

  16. Predictive Estimation of Wireless Link Performance from Medium Physical Parameters

    E-print Network

    Paris-Sud XI, Université de

    in the protected environment of an anechoic room. This way, we generated different medium conditions and collected. It is built in an anechoic chamber to fully control the experimental environment, and avoid external signals

  17. Study of combustion in a divided chamber turbocharged diesel engine by experimental heat release analysis in its chambers

    Microsoft Academic Search

    C. D. Rakopoulos; K. A. Antonopoulos; D. C. Rakopoulos; E. G. Giakoumis

    2006-01-01

    A heat release analysis of experimental pressure diagrams, appropriate for divided chamber diesel engines, is developed and used to obtain heat release rate profiles during the combustion process in each of the two combustion chambers. Attention is paid to the correct processing of the data, due to the inherent complexity of the mass interchange between the two chambers. The analysis

  18. Plant growth chamber based on space proven controlled environment technology

    NASA Astrophysics Data System (ADS)

    Ignatius, Ronald W.; Ignatius, Matt H.; Imberti, Henry J.

    1997-01-01

    Quantum Devices, Inc., in conjunction with Percival Scientific, Inc., and the Wisconsin Center for Space Automation and Robotics (WCSAR) have developed a controlled environment plant growth chamber for terrestrial agricultural and scientific applications. This chamber incorporates controlled environment technology used in the WCSAR ASTROCULTURE™ flight unit for conducting plant research on the Space Shuttle. The new chamber, termed CERES 2010, features air humidity, temperature, and carbon dioxide control, an atmospheric contaminant removal unit, an LED lighting system, and a water and nutrient delivery system. The advanced environment control technology used in this chamber will increase the reliability and repeatability of environmental physiology data derived from plant experiments conducted in this chamber.

  19. New drift chamber for the Mark II at SLC

    SciTech Connect

    Hanson, G.G.

    1984-04-01

    A new cylindrical drift chamber is being constructed for the Mark II detector for use at the new SLAC Linear Collider. The design of the new chamber is based on a multi-sense-wire cell of the jet-chamber type. In addition to drift-time measurements, pulse height measurements from the sense wires will provide electron-hadron separation by dE/dx. The design and construction of the chamber, tests of prototypes, and chamber electronics are discussed. 7 references, 12 figures.

  20. New central drift chamber for the MARK II at SLC

    SciTech Connect

    Bartelt, J.E.

    1986-09-01

    A new central drift chamber has been constructed for the Mark II detector for use at the new SLAC Linear Collider (SLC). The design of the chamber is based on a multi-sense-wire cell of the jet chamber type. In addition to drift-time measurements, pulse-height measurements from the sense wires provide electron-hadron separation by dE/dx. The chamber has been tested in operation at PEP before its move to the SLC. The design and construction are described, and measurements from the new chamber are presented.

  1. Advanced Modified High Performance Synthetic Jet Actuator with Curved Chamber

    NASA Technical Reports Server (NTRS)

    Xu, Tian-Bing (Inventor); Su, Ji (Inventor); Jiang, Xiaoning (Inventor)

    2014-01-01

    The advanced modified high performance synthetic jet actuator with optimized curvature shape chamber (ASJA-M) is a synthetic jet actuator (SJA) with a lower volume reservoir or chamber. A curved chamber is used, instead of the conventional cylinder chamber, to reduce the dead volume of the jet chamber and increase the efficiency of the synthetic jet actuator. The shape of the curvature corresponds to the maximum displacement (deformation) profile of the electroactive diaphragm. The jet velocity and mass flow rate for the ASJA-M will be several times higher than conventional piezoelectric actuators.

  2. Measurements of x-ray scattering from accelerator vacuum chamber surfaces, and comparison with an analytical model

    NASA Astrophysics Data System (ADS)

    Dugan, G. F.; Sonnad, K. G.; Cimino, R.; Ishibashi, T.; Schäfers, F.

    2015-04-01

    This paper compares measurements and calculations of scattering of photons from technical vacuum chamber surfaces typical of accelerators. Synchrotron radiation generated by a charged particle beam in the accelerator is either absorbed, specularly reflected, or scattered by the vacuum chamber surface. This phenomenon has important implications on the operation of the accelerator. Measurements of photon scattering were made at the BESSY-II synchrotron radiation facility using samples of aluminum vacuum chamber from Cornell electron storage ring (CESR). A description of the analytic model used in the calculation is given, which takes into account the reflectivity of the material, the surface features of the sample, the wavelengths and the incident angles of the photons. The surface properties used in these calculations were obtained from measurements made from an atomic force microscope.

  3. Boeing infrared sensor (BIRS) calibration facility

    NASA Technical Reports Server (NTRS)

    Hazen, John D.; Scorsone, L. V.

    1990-01-01

    The Boeing Infrared Sensor (BIRS) Calibration Facility represents a major capital investment in optical and infrared technology. The facility was designed and built for the calibration and testing of the new generation large aperture long wave infrared (LWIR) sensors, seekers, and related technologies. Capability exists to perform both radiometric and goniometric calibrations of large infrared sensors under simulated environmental operating conditions. The system is presently configured for endoatmospheric calibrations with a uniform background field which can be set to simulate the expected mission background levels. During calibration, the sensor under test is also exposed to expected mission temperatures and pressures within the test chamber. Capability exists to convert the facility for exoatmospheric testing. The configuration of the system is described along with hardware elements and changes made to date are addressed.

  4. Liquid rocket engine self-cooled combustion chambers

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Self-cooled combustion chambers are chambers in which the chamber wall temperature is controlled by methods other than fluid flow within the chamber wall supplied from an external source. In such chambers, adiabatic wall temperature may be controlled by use of upstream fluid components such as the injector or a film-coolant ring, or by internal flow of self-contained materials; e.g. pyrolysis gas flow in charring ablators, and the flow of infiltrated liquid metals in porous matrices. Five types of self-cooled chambers are considered in this monograph. The name identifying the chamber is indicative of the method (mechanism) by which the chamber is cooled, as follows: ablative; radiation cooled; internally regenerative (Interegen); heat sink; adiabatic wall. Except for the Interegen and heat sink concepts, each chamber type is discussed separately. A separate and final section of the monograph deals with heat transfer to the chamber wall and treats Stanton number evaluation, film cooling, and film-coolant injection techniques, since these subjects are common to all chamber types. Techniques for analysis of gas film cooling and liquid film cooling are presented.

  5. Measurements of a 1/4-scale model of a 60-kg explosives firing chamber

    SciTech Connect

    Pastrnak, J.W.; Baker, C.F.; Simmons, L.F.

    1995-01-27

    In anticipation of increasingly stringent environmental regulations, Lawrence Livermore National Laboratory (LLNL) proposes to construct a 60-kg firing chamber to provide blast-effects containment for, most of its open-air, high-explosive, firing operations. Even though these operations are within current environmental limits, containment of the blast effects and hazardous debris will further drastically reduce emissions to the environment and minimize the generated hazardous waste. The major design consideration of such a chamber is its overall structural dynamic response in terms of long-term containment of all blast effects from repeated internal detonations of high explosives. Another concern is how much other portions of the facility must be hardened to ensure personnel protection in the event of an accidental detonation. To assess these concerns, a 1/4-scale replica model of the planned contained firing chamber was designed, constructed, and tested with scaled explosive charges ranging from 25 to 125% of the operational explosives limit of 60 kg. From 16 detonations of high explosives, 880 resulting strains, blast pressures, and temperatures within the model were measured. Factors of safety for dynamic yield of the firing chamber structure were calculated and compared to the design criterion of totally elastic response. The rectangular, reinforced-concrete chamber model exhibited a lightly damped vibrational response that placed the structure in alternating cycles of tension and compression. During compression, both the reinforcing steel and the concrete remained elastic. During tension, the reinforcing steel remained elastic, but the concrete elastic limit was exceeded in two areas, the center spans of the ceiling and the north wall, where elastic safety factors as low as 0.66 were obtained, thus indicating that the concrete would be expected to crack in those areas. Indeed, visual post-test inspection of those areas revealed tight cracks in the concrete.

  6. Vacuum chamber with a supersonic-flow aerodynamic window

    DOEpatents

    Hanson, C.L.

    1980-10-14

    A supersonic flow aerodynamic window is disclosed whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

  7. Vacuum chamber with a supersonic flow aerodynamic window

    DOEpatents

    Hanson, Clark L. (Livermore, CA)

    1982-01-01

    A supersonic flow aerodynamic window, whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

  8. Investigation on temperature separation and flow behaviour in vortex chamber

    NASA Astrophysics Data System (ADS)

    Matsuno, Yuhi; Fukushima, Yusuke; Matsuo, Shigeru; Hashimoto, Tokitada; Setoguchi, Toshiaki; Kim, Heuy Dong

    2015-04-01

    In the previous researches, it is known that the swirl flow in circular pipe causes the temperature separation. Recently, it is shown that the temperature separation occurs in a vortex chamber when compressed air are pumped into this device from the periphery. Especially, in a cavity installed in the periphery of the chamber, the highest temperature was observed. Therefore, it is expected that this device can be used as a heat source in the engineering field. In recent researches, the mechanism of temperature separation in vortex chamber has been investigated by some researchers. However, there are few researches for the effect of diameter and volume of vortex chamber, height of central rod and position of cavity on the temperature separation. Further, no detailed physical explanation has been made for the temperature separation phenomena in the vortex chamber. In the present study, the effects of chamber configuration and position of the cavity on temperature separation in the vortex chamber were investigated experimentally.

  9. A new combustion chamber for fast-burn applications

    SciTech Connect

    Evans, R.L.; Cameron, C.

    1986-01-01

    A new combustion chamber design is proposed in which it is possible to control the scale and intensity of turbulence generated just prior to ignition. A single cylinder engine has been fitted with the new chamber, and measurements of the turbulence field with a hot-wire anemometer are presented. The chamber design has been compared to a conventional bowl-in-piston design under both motoring and fired operation. Hot-wire measurements showed an increase in turbulence intensity of 50% and a reduction in the length scale of turbulence compared to the conventional chamber. Cylinder pressure measurements indicated that the mass-burn rate is increased with the new chamber, particularly during the early stage of combustion. During operation at 1140 rpm with the new chamber, peak cylinder pressure was 4% higher and occurred 3/sup 0/ earlier than for the conventional chamber.

  10. Energy Systems Test Area (ESTA). Power Systems Test Facilities

    NASA Technical Reports Server (NTRS)

    Situ, Cindy H.

    2010-01-01

    This viewgraph presentation provides a detailed description of the Johnson Space Center's Power Systems Facility located in the Energy Systems Test Area (ESTA). Facilities and the resources used to support power and battery systems testing are also shown. The contents include: 1) Power Testing; 2) Power Test Equipment Capabilities Summary; 3) Source/Load; 4) Battery Facilities; 5) Battery Test Equipment Capabilities Summary; 6) Battery Testing; 7) Performance Test Equipment; 8) Battery Test Environments; 9) Battery Abuse Chambers; 10) Battery Abuse Capabilities; and 11) Battery Test Area Resources.

  11. The influence of the type of filling gas on the response of ionisation chambers to a mixed high-energy radiation field.

    PubMed

    Mayer, S; Forkel-Wirth, D; Fuerstner, M; Roesler, S; Theis, C; Vincke, H

    2007-01-01

    Radiation protection dosimetry in radiation fields behind the shielding of high-energy accelerators such as CERN is a challenging task and the quantitative understanding of the detector response used for dosimetry is essential. Measurements with ionisation chambers are a standard method to determine absorbed dose (in the detector material). For applications in mixed radiation fields, ionisation chambers are often also calibrated in terms of ambient dose equivalent at conventional reference radiation fields. The response of a given ionisation chamber to the various particle types of a complex high-energy radiation field in terms of ambient dose equivalent depends of course on the materials used for the construction and the chamber gas used. This paper will present results of computational studies simulating the exposure of high-pressure ionisation chambers filled with different types of gases to the radiation field at CERN's CERN-EU high-energy reference field facility. At this facility complex high-energy radiation fields, similar to those produced by cosmic rays at flight altitudes, are produced. The particle fluence and spectra calculated with FLUKA Monte Carlo simulations have been benchmarked in several measurements. The results can be used to optimise the response of ionisation chambers for the measurement of ambient dose equivalent in high-energy mixed radiation fields. PMID:17575292

  12. Finite Element Analysis of Reverberation Chambers

    NASA Technical Reports Server (NTRS)

    Bunting, Charles F.; Nguyen, Duc T.

    2000-01-01

    The primary motivating factor behind the initiation of this work was to provide a deterministic means of establishing the validity of the statistical methods that are recommended for the determination of fields that interact in -an avionics system. The application of finite element analysis to reverberation chambers is the initial step required to establish a reasonable course of inquiry in this particularly data-intensive study. The use of computational electromagnetics provides a high degree of control of the "experimental" parameters that can be utilized in a simulation of reverberating structures. As the work evolved there were four primary focus areas they are: 1. The eigenvalue problem for the source free problem. 2. The development of a complex efficient eigensolver. 3. The application of a source for the TE and TM fields for statistical characterization. 4. The examination of shielding effectiveness in a reverberating environment. One early purpose of this work was to establish the utility of finite element techniques in the development of an extended low frequency statistical model for reverberation phenomena. By employing finite element techniques, structures of arbitrary complexity can be analyzed due to the use of triangular shape functions in the spatial discretization. The effects of both frequency stirring and mechanical stirring are presented. It is suggested that for the low frequency operation the typical tuner size is inadequate to provide a sufficiently random field and that frequency stirring should be used. The results of the finite element analysis of the reverberation chamber illustrate io-W the potential utility of a 2D representation for enhancing the basic statistical characteristics of the chamber when operating in a low frequency regime. The basic field statistics are verified for frequency stirring over a wide range of frequencies. Mechanical stirring is shown to provide an effective frequency deviation.

  13. Condensate Recycling in Closed Plant Growth Chambers

    NASA Technical Reports Server (NTRS)

    Bledsoe, J. O.; Sager, J. C.; Fortson, R. E.

    1994-01-01

    Water used in the the Controlled Ecological Life Support System (CELSS) Breadboard Project at the Kennedy Space Center is being recycled. Condensation is collected in the air ducts, filtered and deionized, and resupplied to the system for nutrient solutions, supplemental humidification, solvents and diluents. While the system functions well from a process control standpoint, precise and accurate tracking of water movement through the system to answer plant physiological questions is not consistent. Possible causes include hardware errors, undetected vapor loss from chamber leakage, and unmeasured changes in water volume in the plant growth trays.

  14. A spark chamber for cosmic ray research

    E-print Network

    Jelinek, Al Vincent

    1964-01-01

    . The Geiger counters used in this apparatus are made of soft (soda lime) glass tubing 1 I/2" in diameter, 18" long with center wires of 5-mil tungsten. The tubes were coated with Dag 3isper- sion No. 194 conducting lacquer to form an exterior cathode... . Tne sp -rk i ~ a, h. ghly conducting plasma. w. :n 1 ov imoed ance aru the high-vol . age terminal of cne caps citor bans i" effoc ively grounded, sv' tcning tne hign-voliage on the c" pacitor 'sank across the chamber. This volta ~ c wil: c se...

  15. Vacuum chamber for containing particle beams

    DOEpatents

    Harvey, Alexander (Los Alamos, NM)

    1987-01-01

    A vacuum chamber for containing a charged particle beam in a rapidly changing magnetic environment comprises a ceramic pipe with conducting strips oriented along the longitudinal axis of the pipe and with circumferential conducting bands oriented perpendicular to the longitudinal axis but joined with a single longitudinal electrical connection. When both strips and bands are on the outside of the ceramic pipe, insulated from each other, a high-resistance conductive layer, such as nickel can be coated on the inside of the pipe.

  16. Vacuum chamber for containing particle beams

    DOEpatents

    Harvey, A.

    1985-11-26

    A vacuum chamber for containing a charged particle beam in a rapidly changing magnetic environment comprises a ceramic pipe with conducting strips oriented along the longitudinal axis of the pipe and with circumferential conducting bands oriented perpendicular to the longitudinal axis but joined with a single longitudinal electrical connection. When both strips and bands are on the outside of the ceramic pipe, insulated from each other, a high-resistance conductive layer such as nickel can be coated on the inside of the pipe.

  17. Streamer studies in Resistive Plate Chambers

    NASA Astrophysics Data System (ADS)

    Denni, U.; Felici, G.; Frani, M. A.; Mengucci, A.; Papalino, G.; Spinetti, M.; Paoloni, A.

    2011-06-01

    Resistive Plate Chambers (RPCs) are widely used in high energy physics. While avalanche mode operation is mandatory in high rate environments (ATLAS and CMS experiments at LHC), streamer mode operation is often preferred in low rate applications because of the high signal amplitude. Typical mixtures for streamer operation are composed of Argon, Tetrafluoroethane and Isobutane, with additions of SF 6 below 1% to reduce the charge delivered in the gas. In this paper, results about the streamer properties observed with different mixtures are presented.

  18. Space shuttle orbit maneuvering engine reusable thrust chamber: Adverse operating conditions test report

    NASA Technical Reports Server (NTRS)

    Tobin, R. D.

    1974-01-01

    Test hardware, facilities, and procedures are described along with results of electrically heated tube and channel tests conducted to determine adverse operating condition limits for convectively cooled chambers typical of Space Shuttle Orbit Manuevering Engine designs. Hot-start tests were conducted with corrosion resistant steel and nickel tubes with both monomethylhydrazine and 50-50 coolants. Helium ingestion, in both bubble and froth form, was studied in tubular test sections. Helium bubble ingestion and burn-out limits in rectangular channels were also investigated.

  19. Accumulation of spatial charge in the time projection chamber of a multipurpose detector

    NASA Astrophysics Data System (ADS)

    Merts, S. P.; Razin, S. V.; Rogachevskii, O. V.

    2013-01-01

    This article presents the results of a numerical simulation of the process of spatial positive charge accumulation in the Time Projection Chamber (TPC) of the multipurpose detector (MPD) at Nuclotron-based Ion Collider fAcility (NICA) at the Joint Institute for Nuclear Research (JINR). Based on the spatial distribution of the charges, the problem of calculating the potential of the electrostatic field created by these charges has been solved. The radial, angular, and axial distortions in the electron motions from the point of ionization to the readout planes are calculated.

  20. A new multi-strip ionization chamber used as online beam monitor for heavy ion therapy

    NASA Astrophysics Data System (ADS)

    Xu, Zhiguo; Mao, Ruishi; Duan, Limin; She, Qianshun; Hu, Zhengguo; Li, He; Lu, Ziwei; Zhao, Qiecheng; Yang, Herun; Su, Hong; Lu, Chengui; Hu, Rongjiang; Zhang, Junwei

    2013-11-01

    A multi-strip ionization chamber has been built for precise and fast monitoring of the carbon beam spatial distribution at Heavy Ion Researched Facility of Lanzhou Cooling Storing Ring (HIRFL-CSR). All the detector's anode, cathode and sealed windows are made by 2 ?m aluminized Mylar film in order to minimize the beam lateral deflection. The sensitive area of the detector is (100×100) mm2, with the anode segmented in 100 strips, and specialized front-end electronics has been developed for simplifying the data acquisition and quick feedback of the relevant parameters to beam control system. It can complete one single beam profile in 200 ?s.

  1. Overview of the National Ignition Facility.

    PubMed

    Brereton, Sandra

    2013-06-01

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is the world's largest and most energetic laser system for inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. The NIF is a 192-beam, Nd-glass laser facility that is capable of producing 1.8 MJ, 500 TW of ultraviolet light, and over 50 times more energetic than other existing ICF facilities. The NIF construction began in 1997, and the facility, which was completed in 2009, is now fully operational. The facility is capable of firing up to 192 laser beams onto a target placed at the center of a 10-m-diameter spherical target chamber. Experiments involving the use of tritium have been underway for some time. These experiments present radiological issues: prompt neutron/gamma radiation, neutron activation, fission product generation, and decay radiation. This paper provides an introduction to the NIF facility and its operation, describes plans for the experimental program, and discusses radiological issues associated with the NIF's operations. PMID:23629059

  2. Modeling of Solid Waste Flow and Mixing on the Traveling Grate of a Waste-to- energy Combustion Chamber

    Microsoft Academic Search

    MASATO NAKAMURA; N. J. THEMELIS

    Mixing of the highly non-homogeneous municipal solid wastes (MSW) on the traveling grate of mass-burn combustion chambers assists the combustion process in waste-to-energy (WTE) facilities. A matrix-based Markov chain model was developed to simulate particle flow and mixing as the solid waste particles travel over a reverse acting Martin grate. The model was used to project the pathway of a

  3. Vapor Wall Deposition in Chambers: Theoretical Considerations

    NASA Astrophysics Data System (ADS)

    McVay, R.; Cappa, C. D.; Seinfeld, J.

    2014-12-01

    In order to constrain the effects of vapor wall deposition on measured secondary organic aerosol (SOA) yields in laboratory chambers, Zhang et al. (2014) varied the seed aerosol surface area in toluene oxidation and observed a clear increase in the SOA yield with increasing seed surface area. Using a coupled vapor-particle dynamics model, we examine the extent to which this increase is the result of vapor wall deposition versus kinetic limitations arising from imperfect accommodation of organic species into the particle phase. We show that a seed surface area dependence of the SOA yield is present only when condensation of vapors onto particles is kinetically limited. The existence of kinetic limitation can be predicted by comparing the characteristic timescales of gas-phase reaction, vapor wall deposition, and gas-particle equilibration. The gas-particle equilibration timescale depends on the gas-particle accommodation coefficient ?p. Regardless of the extent of kinetic limitation, vapor wall deposition depresses the SOA yield from that in its absence since vapor molecules that might otherwise condense on particles deposit on the walls. To accurately extrapolate chamber-derived yields to atmospheric conditions, both vapor wall deposition and kinetic limitations must be taken into account.

  4. Mass spectrometer use in a large chamber

    NASA Astrophysics Data System (ADS)

    Chuvala, Tom

    1992-11-01

    The early satellites were somewhat insensitive to contamination produced during the construction and testing phases. The On-Orbit lifetime was such that contamination effects went either unnoticed or unrecognized. With today's On-Orbit lifetimes approaching 10+ years, contamination has become a paramount concern. The scientific payloads have increased in complexity and sensitivity. The ability to clean a contaminated sensor has greatly diminished. This requires better pumping systems and methods for improved monitoring. The conversion from diffusion pumped thermal vacuum chambers to cryo pumped chambers with the use of Misner traps and selective cold traps has reduced contamination. Witness samples supply a record of the condensates that remain after a testing cycle, but impart no knowledge of the contaminant migration during the cycle that may be a month in duration. Due to a customer's request that mass spectrometry be used during the testing of their spacecraft, a consultant was contracted to install a mass spectrometer to determine the feasibility of the instrument. The equipment and methodology described will start with the original system and its evolution to GE's present system.

  5. Mass spectrometer use in a large chamber

    NASA Technical Reports Server (NTRS)

    Chuvala, Tom

    1992-01-01

    The early satellites were somewhat insensitive to contamination produced during the construction and testing phases. The On-Orbit lifetime was such that contamination effects went either unnoticed or unrecognized. With today's On-Orbit lifetimes approaching 10+ years, contamination has become a paramount concern. The scientific payloads have increased in complexity and sensitivity. The ability to clean a contaminated sensor has greatly diminished. This requires better pumping systems and methods for improved monitoring. The conversion from diffusion pumped thermal vacuum chambers to cryo pumped chambers with the use of Misner traps and selective cold traps has reduced contamination. Witness samples supply a record of the condensates that remain after a testing cycle, but impart no knowledge of the contaminant migration during the cycle that may be a month in duration. Due to a customer's request that mass spectrometry be used during the testing of their spacecraft, a consultant was contracted to install a mass spectrometer to determine the feasibility of the instrument. The equipment and methodology described will start with the original system and its evolution to GE's present system.

  6. Wire chamber radiation detector with discharge control

    DOEpatents

    Perez-Mendez, Victor (Berkeley, CA); Mulera, Terrence A. (Berkeley, CA)

    1984-01-01

    A wire chamber radiation detector (11) has spaced apart parallel electrodes (16) and grids (17, 18, 19) defining an ignition region (21) in which charged particles (12) or other ionizing radiations initiate brief localized avalanche discharges (93) and defining an adjacent memory region (22) in which sustained glow discharges (94) are initiated by the primary discharges (93). Conductors (29, 32) of the grids (18, 19) at each side of the memory section (22) extend in orthogonal directions enabling readout of the X-Y coordinates of locations at which charged particles (12) were detected by sequentially transmitting pulses to the conductors (29) of one grid (18) while detecting transmissions of the pulses to the orthogonal conductors (36) of the other grid (19) through glow discharges (94). One of the grids (19) bounding the memory region (22) is defined by an array of conductive elements (32) each of which is connected to the associated readout conductor (36) through a separate resistance (37). The wire chamber (11) avoids ambiguities and imprecisions in the readout of coordinates when large numbers of simultaneous or near simultaneous charged particles (12) have been detected. Down time between detection periods and the generation of radio frequency noise are also reduced.

  7. Hand discomfort following heliox chamber dives.

    PubMed

    Benton, Peter J; Anthony, Gavin

    2003-10-01

    During a series of dry chamber dives using compressed heliox, five attendants and one wet diver experienced eight episodes of hand discomfort, the character of which was atypical of limb pain during decompression sickness. Although immersed for most of the dive, during the compression and decompression phases, the wet diver's hands were out of the water and hence exposed to the helium-containing chamber atmosphere. In all cases, symptoms resolved within a maximum of 48 h. There was no response to hyperbaric oxygen therapy in the three cases that presented before spontaneous resolution. While the attendants wore dry suits to minimize skin absorption of helium, their hands, were exposed to the heliox atmosphere. After the first six cases of hand symptoms, a dry glove assembly was added to prevent helium absorption through the exposed hand. Two cases of hand discomfort occurred following the addition of the dry glove assembly to the dry suit. In both cases, the symptoms were less severe and resolved over a significantly shorter time period. Adoption of the dry gloves resulted in the incidence of hand discomfort among attendants falling from 25% (5/20) to 2.4% (2/84) (p = 0.005). Possible mechanisms of causation of this hand discomfort, thought to be the result of local tissue absorption of helium, are discussed. PMID:14556574

  8. Rocket thrust chamber thermal barrier coatings

    NASA Technical Reports Server (NTRS)

    Batakis, A. P.; Vogan, J. W.

    1985-01-01

    A research program was conducted to generate data and develop analytical techniques to predict the performance and reliability of ceramic thermal barrier coatings in high heat flux environments. A finite element model was used to analyze the thermomechanical behavior of coating systems in rocket thrust chambers. Candidate coating systems (using a copper substrate, NiCrAlY bond coat and ZrO2.8Y2O3 ceramic overcoat) were selected for detailed study based on photomicrographic evaluations of experimental test specimens. The effects of plasma spray application parameters on the material properties of these coatings were measured and the effects on coating performance evaluated using the finite element model. Coating design curves which define acceptable operating envelopes for seleted coating systems were constructed based on temperature and strain limitations. Spray gun power levels was found to have the most significant effect on coating structure. Three coating systems were selected for study using different power levels. Thermal conductivity, strain tolerance, density, and residual stress were measured for these coatings. Analyses indicated that extremely thin coatings ( 0.02 mm) are required to accommodate the high heat flux of a rocket thrust chamber and ensure structural integrity.

  9. Description of new vacuum chamber correction concept

    SciTech Connect

    Danby, G.T.; Jackson, J.W.

    1989-01-01

    For rapid cycled accelerators eddy currents induced in vacuum chambers (VC) are typically the dominant source of systematic and random field aberrations. Complex thin wall VC are expensive and delicate where bakeout is required, as in the AGS Booster under construction. Thick wall VC are rugged and economical but produce large eddy currents. A ''Self-Correction'' concept has been developed and tested which corrects automatically by transformer action, even for variable /dot B/ cycles. Coils attached to the outside of the VC cancel eddy current aberrations over the entire ''good field'' aperture. The (inexpensive) correction coils follow the local contour of the VC, so large transverse VC movements are tolerated; both the aberrations and their corrections have the same displaced coordinates. Experimental results are presented for Booster correction coil designs demonstrating both self-correction and excitation by a separate power supply. Analytic results applicable to the Booster and other fast cycling accelerators are discussed. The eddy current field aberrations induced in a pre-production full size vacuum chamber inserted in an AGS Booster dipole have been successfully eliminated by the ''self correction'' coils attached to its surface. The voltage induced in a two-turns per pole ''back leg'' winding is sufficient to supply the necessary current through the correction winding. A nichrome wire attached in series provides adjustable resistance for current control. 2 refs., 7 figs.

  10. Vacuum chamber for treating workpieces with beams

    SciTech Connect

    Ryding, G.

    1980-10-21

    Apparatus is described for directing a beam at a workpiece in vacuum has a special planar sliding multiple seal arrangement that enables repeated scanning movement of the workpiece across the beam. The seal includes a planar slide plate and an opposed relatively movable seal support member, also preferrably a plate parallel to the slide plate. Aligned apertures are in the members, one of which is larger in the direction of relative movement than the other enabling the relative movement while maintaining the alignment. A plurality of concentric resilient seals, which may be of oval race track configuration, bear with a sliding contact against the planar surface, these seals preferably comprising composites of a thin high density polyethylene seal element and a soft and only milding compressed backing element that applies a feather-light seal pressure. Between-seal pumping is provided to reduce the differential pressure across any seal to to remove gas that may leak into the space. The embodiment shown incorporates the seal between a moving target chamber and a fixed ion beam chamber.

  11. High density avalanche chamber (HIDAC) positron camera.

    PubMed

    Townsend, D; Frey, P; Jeavons, A; Reich, G; Tochon-Danguy, H J; Donath, A; Christin, A; Schaller, G

    1987-10-01

    A prototype positron camera has been constructed consisting of two high density avalanche chamber (HIDAC) detectors operated in coincidence with a resolving time (2 tau) of 40 nsec. The detectors are multiwire chambers, with specially constructed lead converters added to improve the photon detection efficiency at 511 keV. The current HIDAC detectors have a singles efficiency of approximately 12%, a sensitive area of 31 X 31 cm and an intrinsic spatial resolution of less than 2 mm full width at half maximum (FWHM). During data acquisition, the detectors are rotated around the patient in order to collect a complete angular data set. A three-dimensional image of the positron distribution is reconstructed from a single scan by weighted backprojection of the data into a matrix of either 64 X 64 X 64 or 128 X 128 X 16 voxels. The camera point response function is deconvolved by frequency-space filtering. Corrections are made during backprojection both for photon attenuation and for spatial variations in point source sensitivity. The reconstructed image is further corrected for contributions from accidental and scattered coincidences and displayed as a sequence of two-dimensional transverse, sagittal, or coronal sections. In addition, three-dimensional display is available using shaded graphics techniques. The prototype camera is currently undergoing clinical evaluation. PMID:3498804

  12. EFFECTS OF ACTIVATED CHARCOAL FILTRATION AND OZONATION ON HYDROCARBON AND CARBONYL LEVELS OF AMBIENT AIR USED IN CONTROLLED-EXPOSURE CHAMBER STUDIES OF AIR POLLUTANT HUMAN HEALTH EFFECTS

    EPA Science Inventory

    Air sampling experiments were done in 1985, 1987, and 1993 at the human-exposure chamber facility of the U.S. EPA Health Effects Research Laboratory in Chapel Hill, NC. easurements of VOC's by GC-FID and aldehyde measurements by the DNPH silica gel cartridge method were made, com...

  13. Facility Focus: Sports and Recreation Facilities.

    ERIC Educational Resources Information Center

    College Planning & Management, 2000

    2000-01-01

    Examines projects that demonstrate three different commitments administrators make to their athletic facilities: convenience; excellence; and comfort. Projects discussed involve a fitness center, a football stadium, and a multi-sport indoor practice facility. (GR)

  14. Measurement and Compensation of BPM Chamber Motion in HLS

    SciTech Connect

    Li, J. W.; Sun, B. G.; Cao, Y.; Xu, H. L.; Lu, P.; Li, C.; Xuan, K.; Wang, J. G. [NSRL, School of Nuclear Science and Technology, University of Science and Technology of China Hefei, Anhui230029 (China)

    2010-06-23

    Significant horizontal drifts in the beam orbit in the storage ring of HLS (Hefei Light Source) have been seen for many years. What leads to the motion of Beam Position Monitor (BPM) chamber is thermal expansion mainly caused by the synchrotron light. To monitor the BPM chamber motions for all BPMs, a BPM chamber motion measurement system is built in real-time. The raster gauges are used to measure the displacements. The results distinctly show the relation between the BPM chamber motion and the beam current. To suppress the effect of BPM chamber motion, a compensation strategy is implemented at HLS. The horizontal drifts of beam orbit have been really suppressed within 20{mu}m without the compensation of BPM chamber motion in the runtime.

  15. Measurement and Compensation of BPM Chamber Motion in HLS

    NASA Astrophysics Data System (ADS)

    Li, J. W.; Sun, B. G.; Cao, Y.; Xu, H. L.; Lu, P.; Li, C.; Xuan, K.; Wang, J. G.

    2010-06-01

    Significant horizontal drifts in the beam orbit in the storage ring of HLS (Hefei Light Source) have been seen for many years. What leads to the motion of Beam Position Monitor (BPM) chamber is thermal expansion mainly caused by the synchrotron light. To monitor the BPM chamber motions for all BPMs, a BPM chamber motion measurement system is built in real-time. The raster gauges are used to measure the displacements. The results distinctly show the relation between the BPM chamber motion and the beam current. To suppress the effect of BPM chamber motion, a compensation strategy is implemented at HLS. The horizontal drifts of beam orbit have been really suppressed within 20?m without the compensation of BPM chamber motion in the runtime.

  16. R2 REGULATED FACILITIES

    EPA Science Inventory

    The Facility Registry System (FRS) is a centrally managed database that identifies facilities, sites or places subject to environmental regulations or of environmental interest. FRS creates high-quality, accurate, and authoritative facility identification records through rigorous...

  17. Experience with the jet chamber of the JADE-experiment

    SciTech Connect

    Heuer, R.D.

    1984-01-01

    The jet chamber, a pictorial drift chamber used as the central track detector of the JADE experiment at PETRA, is briefly described. The present status of the spatial and dE/dx resolutions and the experience during 4 years of operation is reported. Improvement plans for the readout electronics are described and a short review of the jet chamber designed for the proposed LEP experiment OPAL is given.

  18. Thermal diffusion cloud chamber-new criteria for proper operation

    Microsoft Academic Search

    Richard H. Heist; Daniel Martinez; Yuk Chan; Anne Bertelsmann

    2000-01-01

    We report results of new nucleation experiments involving 1-pentanol with hydrogen as the background gas utilizing the high-pressure diffusion cloud chamber (HPCC). We discuss the important issue of buoyancy-driven convective motion and cloud chamber operation, and we focus on the lower total pressure limit required for stable chamber operation. We provide, for the first time, an empirical procedure for determining

  19. A new combustion chamber for fast-burn applications

    Microsoft Academic Search

    R. L. Evans; C. Cameron

    1986-01-01

    A new combustion chamber design is proposed in which it is possible to control the scale and intensity of turbulence generated just prior to ignition. A single cylinder engine has been fitted with the new chamber, and measurements of the turbulence field with a hot-wire anemometer are presented. The chamber design has been compared to a conventional bowl-in-piston design under

  20. Transient response characteristics of test chamber Mach number

    NASA Technical Reports Server (NTRS)

    Tcheng, P.

    1976-01-01

    The transient dynamic characteristics of a test chamber Mach number was established for a disturbance initiated in the test chamber. An approximate linear expression was given, showing that the change in the Mach number is linearly proportional to the algebraic sum of the static pressure change in the test chamber and the stagnation pressure change. The static pressure change is the dominating factor. The two pressure changes were also calculated for small Mach number variations, and these results were applied to instrumentation requirements.

  1. 8. SEDIMENTATION CHAMBER, VIEW UPSTREAM (PLANK COVER REMOVED FOR CLARITY). ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. SEDIMENTATION CHAMBER, VIEW UPSTREAM (PLANK COVER REMOVED FOR CLARITY). BOX FLUME DROPS SLIGHTLY INTO CHAMBER ON LEFT SIDE. CHAMBER IS A SERIES OF BAFFLES DESIGNED TO SLOW THE FLOW OF WATER. FLOW IS REDUCED TO ALLOW PARTICULATES TO SETTLE TO THE BOTTOM. TWO SCREENS (NOT SHOWN) FILTER LARGER DEBRIS. - Kalaupapa Water Supply System, Waikolu Valley to Kalaupapa Settlement, Island of Molokai, Kalaupapa, Kalawao County, HI

  2. NASA Teams With Army in Vortex Combustion Chamber Engine Test

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This photograph depicts one of over thirty tests conducted on the Vortex Combustion Chamber Engine at Marshall Space Flight Center's (MSFC) test stand 115, a joint effort between NASA's MSFC and the U.S. Army AMCOM of Redstone Arsenal. The engine tests were conducted to evaluate an irnovative, 'self-cooled', vortex combustion chamber, which relies on tangentially injected propellants from the chamber wall producing centrifugal forces that keep the relatively cold liquid propellants near the wall.

  3. Tests of a novel design of Resistive Plate Chambers

    NASA Astrophysics Data System (ADS)

    Bilki, B.; Corriveau, F.; Freund, B.; Neubüser, C.; Onel, Y.; Repond, J.; Schlereth, J.; Xia, L.

    2015-05-01

    A novel design of Resistive Plate Chambers (RPCs), using only a single resistive plate, is being proposed. Based on this design, two large size prototype chambers were constructed and were tested with cosmic rays and in particle beams. The tests confirmed the viability of this new approach. In addition to showing an improved single-particle response compared to the traditional 2-plate design, the novel chambers also prove to be suitable for calorimetric applications.

  4. DEFENSE OF MATE AND MATING CHAMBER IN A WOOD ROACH.

    PubMed

    RITTER, H

    1964-03-27

    Studies of the eastern wood roach, Cryptocercus punctulatus, reveal that, under laboratory conditions, the mating chambers in rotten wood are inhabited by mated pairs, the male of which will usually defend the chamber successfully against intruding males by a form of fighting. In every staged contest in which the intruder won the fight, it also won the resident female. Females, as well as unmated males singly inhabiting a chamber, could not be induced to defend against an intruder of either sex. PMID:14107455

  5. Design, construction, and evaluation of a chamber for aerobiology

    Microsoft Academic Search

    Morris A. Levin; Manoucher Shahamat; Yasaman Shahamat; Gerard Stelma; Rita R. Colwell

    1997-01-01

    A chamber was designed and constructed for aeromicrobiology applications. An ultraviolet (UV) radiation source was incorporated\\u000a to sterilize the chamber between trials. Twelve bacterial species originally isolated from air samples and obtained from the\\u000a American Type Culture Collection were tested for efficacy of UV radiation disinfection of the chamber, comprising five Gram-positive\\u000a bacteria, six Gram-negative and one Gram-variable bacterial species.

  6. Full-scale chamber investigation and simulation of air freshener emissions in the presence of ozone.

    PubMed

    Liu, Xiaoyu; Mason, Mark; Krebs, Kenneth; Sparks, Leslie

    2004-05-15

    Volatile organic compound (VOC) emissions from one electrical plug-in type of pine-scented air freshener and their reactions with O3 were investigated in the U.S. Environmental Protection Agency indoor air research large chamber facility. Ozone was generated from a device marketed as an ozone generator air cleaner. Ozone and oxides of nitrogen concentrations and chamber conditions such as temperature, relative humidity, pressure, and air exchange rate were controlled and/or monitored. VOC emissions and some of the reaction products were identified and quantified. Source emission models were developed to predict the time/concentration profiles of the major VOCs (limonene, alpha-pinene, beta-pinene, 3-carene, camphene, benzyl propionate, benzyl alcohol, bornyl acetate, isobornyl acetate, and benzaldehyde) emitted bythe air freshener. Gas-phase reactions of VOCs from the air freshener with O3 were simulated by a photochemical kinetics simulation system using VOC reaction mechanisms and rate constants adopted from the literature. The concentration-time predictions were in good agreement with the data for O3 and VOCs emitted from the air freshener and with some of the primary reaction products. Systematic differences between the predictions and the experimental results were found for some species. Poor understanding of secondary reactions and heterogeneous chemistry in the chamber is the likely cause of these differences. The method has the potential to provide data to predict the impact of O3/VOC interactions on indoor air quality. PMID:15212253

  7. Microwave remote plasma enhanced-atomic layer deposition system with multicusp confinement chamber

    SciTech Connect

    Dechana, A. [Program of Physics and General Science, Faculty of Science and Technology, Songkhla Rajabhat University, Songkhla 90000 (Thailand); Thamboon, P. [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Boonyawan, D., E-mail: dheerawan.b@cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2014-10-15

    A microwave remote Plasma Enhanced-Atomic Layer Deposition system with multicusp confinement chamber is established at the Plasma and Beam Physics research facilities, Chiang Mai, Thailand. The system produces highly-reactive plasma species in order to enhance the deposition process of thin films. The addition of the multicusp magnetic fields further improves the plasma density and uniformity in the reaction chamber. Thus, the system is more favorable to temperature-sensitive substrates when heating becomes unwanted. Furthermore, the remote-plasma feature, which is generated via microwave power source, offers tunability of the plasma properties separately from the process. As a result, the system provides high flexibility in choice of materials and design experiments, particularly for low-temperature applications. Performance evaluations of the system were carried on coating experiments of Al{sub 2}O{sub 3} layers onto a silicon wafer. The plasma characteristics in the chamber will be described. The resulted Al{sub 2}O{sub 3} films—analyzed by Rutherford Backscattering Spectrometry in channeling mode and by X-ray Photoelectron Spectroscopy techniques—will be discussed.

  8. Short-term effects of Q-switched ruby laser on monkey anterior chamber angle

    SciTech Connect

    Bonney, C.H.; Gaasterland, D.E.; Rodrigues, M.M.; Raymond, J.J.; Donohoo, P.

    1982-03-01

    Three Q-switched ruby laser pulses were applied to the trabecular meshwork of 10 monkey eyes. Pulse energies ranging from 20 to 110 mJ were studied. The spot size ranged from 100 to 200 micrometer (in air), and the pulse durations was 28 sec. Gonioscopic examinations showed a graded response from no appreciable change at 20 mJ per pulse to marked disruption of anterior chamber angle structures at 100 mJ or more per pulse. Perfusions done within an hour of treatment showed no consistent alteration of the outflow facility. Scanning electron microscopy demonstrated the graded anterior chamber angle response. No disruption of the angle structures was seen after the 20 mJ treatment, but discrete trabecular damage occurred after treatments with 25 mJ. After pulses equal to or greater than 45 mJ the anterior chamber angle structures were markedly altered. The power density causing extensive tissue disruption was equal to or greater than 150 X 10(8) watts/cm2. In each specimen with an identifiable trabecular lesion, tissue debris and endothelial edema were found on the adjacent inner surface of the cornea. Tearing of Descemet's membrane next to the trabecular meshwork occurred with the 100 mJ pulses.

  9. The NASA Lewis Research Center Water Tunnel Facility

    NASA Technical Reports Server (NTRS)

    Wasserbauer, Charles A.

    1997-01-01

    A water tunnel facility specifically designed to investigate internal fluid duct flows has been built at the NASA Research Center. It is built in a modular fashion so that a variety of internal flow test hardware can be installed in the facility with minimal facility reconfiguration. The facility and test hardware interfaces are discussed along with design constraints for future test hardware. The inlet chamber flow conditioning approach is also detailed. Instrumentation and data acquisition capabilities are discussed. The incoming flow quality has been documented for about one quarter of the current facility operating range. At that range, there is some scatter in the data in the turbulent boundary layer which approaches 10 percent of the duct radius leading to a uniform core.

  10. Neutron Flux Characterization of the Cold Beam PGAA-NIPS Facility at the Budapest Research Reactor

    NASA Astrophysics Data System (ADS)

    Belgya, T.; Kis, Z.; Szentmiklósi, L.

    2014-05-01

    Reliable flux characterization is essential for facilities using neutron beams. Hence, the NIPS station at the Budapest Research Reactor has recently been equipped with neutron-tomographic equipment. The beam can also be characterized by means of a large surface wire chamber and application of the time-of-flight method. The energy distribution was measured at three horizontal positions with the surface wire chamber in pinhole geometry, while the spatial inhomogeneity was determined by means of our new neutron-tomographic equipment.

  11. Secondary beam monitors for the NuMI facility at FNAL

    SciTech Connect

    Kopp, S.; Bishai, M.; Dierckxsens, M.; Diwan, M.; Erwin, A.R.; Harris, D.A.; Indurthy, D.; Keisler, R.; Kostin, M.; Lang, M.; MacDonald, J.; /Brookhaven /Fermilab/Pittsburgh U. /Texas U. /Wisconsin U., Madison; ,

    2006-07-01

    The Neutrinos at the Main Injector (NuMI) facility is a conventional neutrino beam which produces muon neutrinos by focusing a beam of mesons into a long evacuated decay volume. We have built four arrays of ionization chambers to monitor the position and intensity of the hadron and muon beams associated with neutrino production at locations downstream of the decay volume. This article describes the chambers construction, calibration, and commissioning in the beam.

  12. Explosive Containment Chamber Vulnerability to Chemical Munition Fragment Impact

    SciTech Connect

    Benham, R.A.; Fischer, S.H.; Kipp, M.E.; Martinez, R.R.

    1999-02-01

    Scenarios in which the explosive burster charge in a chemical munition accidentally detonates inside demilitarization containment chambers are analyzed. The vulnerability of an inner Auxiliary Pressure Vessel and the primary Explosive Containment Chamber to impact by fragments from the largest explosive charge expected to be placed in these chambers (M426, 8 inch, chemical, 7 lbs Comp B) is evaluated. Numerical (CTH) and empirical (ConWep) codes are used to characterize the munition fragments, and assess the consequences of their impact and penetration on the walls of these vessels. Both pristine and corroded configurations of the munition have been considered, with and without liquid agent fill. When the munition burster charge detonates, munition case fragments impact and perforate the Auxiliary Pressure Vessel wall, resulting in extensive breakup of this inner chamber and the formation of additional fragments. These residual munition case and Auxiliary Pressure Vessel fragments have sufficient mass and velocity to crater the Explosive Containment Chamber inner wall layer, with accompanying localized permanent deformation (bulging) of both the inner and outer chamber walls. The integrity of the Explosive Containment Chamber was retained under all of the APV / munition configurations considered in this study, with no evidence that primary (munition) or secondary (munition and Auxiliary Pressure Vessel) fragments will perforate the inner chamber wall. Limited analyses of munition detonation without the Auxiliary Pressure Vessel present indicate that some munition span fragments could form under those conditions that have sufficient mass and velocity to perforate the inner wall of the Explosive Containment Chamber.

  13. Process for treating syngas using a gas reversing chamber

    SciTech Connect

    Segerstrom, C.C.; Stil, J.H.; Ooms, A.J.; Mink, B.H.; Premel, V.; Gawloski, L.

    1989-08-22

    This patent describes a method for reversing the flow of a synthesis gas containing solids that tend to cause fouling of heat transfer surfaces. The method comprising: passing the synthesis gas from a solid carbonaceous fuel gasification reactor into a gas-reversal space within a chamber; removing the synthesis gas from the gas-reversal space within the chamber in a different direction from the direction of synthesis gas entering the chamber; stopping the flow of synthesis gas to the gas-reversal space; adjusting the volume of the gas-reversal space within the chamber; and resuming the flow of synthesis gas from the gasification reactor.

  14. Contactless Thermal Characterization of High Temperature Test Chamber

    E-print Network

    Szucs, Z; Szekely, Vladimir; Rencz, M

    2008-01-01

    In this paper the methodology and the results of a contactless thermal characterization of a high temperature test chamber will be introduced. The test chamber is used for fatigue testing of different MEMS devices where the homogenous temperature distribution within the close proximity from the heating filaments is very important. Our aim was to characterize the evolving temperature distribution inside the test chamber. In order to achieve smaller time constant a new contactless sensor card was developed. The contactless thermal characterization method introduced in this paper enables in situ heat distribution measurement inside the test chamber during operation, with the detection of potentially uneven heat distribution.

  15. Determination of molecular contamination performance for space chamber tests

    NASA Technical Reports Server (NTRS)

    Scialdone, J. J.

    1973-01-01

    The limitations of chamber tests with regard to the molecular contamination of a spacecraft undergoing vacuum test were examined. The molecular flow conditions existing in the chamber and the parameters dictating the degree of contamination were analyzed. Equations and graphs were developed to show the fraction of molecules returning to the spacecraft out of those emitted and to show other chamber flow parameters as a function of chamber and spacecraft surface molecular pumping and geometric configuration. Type and location of instruments required to measure the outgassing, the degree of contamination, and the returning flows are also discussed.

  16. Discharge Chamber Primary Electron Modeling Activities in Three-Dimensions

    NASA Technical Reports Server (NTRS)

    Steuber, Thomas J.

    2004-01-01

    Designing discharge chambers for ion thrusters involves many geometric configuration decisions. Various decisions will impact discharge chamber performance with respect to propellant utilization efficiency, ion production costs, and grid lifetime. These hardware design decisions can benefit from the assistance of computational modeling. Computational modeling for discharge chambers has been limited to two-dimensional codes that leveraged symmetry for interpretation into three-dimensional analysis. This paper presents model development activities towards a three-dimensional discharge chamber simulation to aid discharge chamber design decisions. Specifically, of the many geometric configuration decisions toward attainment of a worthy discharge chamber, this paper focuses on addressing magnetic circuit considerations with a three-dimensional discharge chamber simulation as a tool. With this tool, candidate discharge chamber magnetic circuit designs can be analyzed computationally to gain insight into factors that may influence discharge chamber performance such as: primary electron loss width in magnetic cusps, cathode tip position with respect to the low magnetic field volume, definition of a low magnetic field region, and maintenance of a low magnetic field region across the grid span. Corroborating experimental data will be obtained from mockup hardware tests. Initially, simulated candidate magnetic circuit designs will resemble previous successful thruster designs. To provide opportunity to improve beyond previous performance benchmarks, off-design modifications will be simulated and experimentally tested.

  17. Investigations of recombination chambers for BNCT beam dosimetry.

    PubMed

    Tulik, P; Golnik, N; Zielczynski, M

    2007-01-01

    A set of cylindrical recombination chambers, including a tissue-equivalent chamber and three graphite chambers filled with different gases-CO(2), N(2) and (10)BF(3), was designed for the dosimetry of therapeutic neutron radiation beams used for BNCT. The separation of the dose components is based on differences of the shape of the saturation curve depending on the LET spectrum of the investigated radiation. The measurements using all the chambers were performed in a reactor beam of NRI ReZ (Czech Republic) and in the reference radiation fields of a (252)Cf radiation source free in air or in filters. PMID:17576649

  18. Space shuttle orbit maneuvering engine reusable thrust chamber program

    NASA Technical Reports Server (NTRS)

    Senneff, J. M.

    1975-01-01

    The feasibility of potential reusable thrust chamber concepts is studied. Propellant condidates were examined and analytically combined with potential cooling schemes. A data base of engine data which would assist in a configuration selection was produced. The data base verification was performed by the demonstration of a thrust chamber of a selected coolant scheme design. A full scale insulated columbium thrust chamber was used for propellant coolant configurations. Combustion stability of the injectors and a reduced size thrust chamber were experimentally verified as proof of concept demonstrations of the design and study results.

  19. Electrodeless drift chambers with 50-cm drift distance

    SciTech Connect

    Ayres, D.S.; Price, L.E.

    1982-08-01

    The electrodeless drift-chamber technique is potentially very useful in applications requiring the drifting of ionization in gas over long distances in narrow channels. Chamber construction is simple and cheap; the technique is well suited to very large detectors operating in low-rate environments. Prototype tests on planar chambers reveal excellent drifting characteristics after the initial charging, but show a substantial degradation of pulse height from cosmic rays over a two-week period. The loss of efficiency appears to be caused by excess charge buildup on the dielectric surfaces of the chamber. Several solutions are suggested.

  20. Hot fire fatigue testing results for the compliant combustion chamber

    NASA Technical Reports Server (NTRS)

    Pavli, Albert J.; Kazaroff, John M.; Jankovsky, Robert S.

    1992-01-01

    A hydrogen-oxygen subscale rocket combustion chamber was designed incorporating an advanced design concept to reduce strain and increase life. The design permits unrestrained thermal expansion of a circumferential direction and, thereby, provides structural compliance during the thermal cycling of hot-fire testing. The chamber was built and test fired at a chamber pressure of 4137 kN/sq m (600 psia) and a hydrogen-oxygen mixture ratio of 6.0. Compared with a conventional milled-channel configuration, the new structurally compliant chamber had a 134 or 287 percent increase in fatigue life, depending on the life predicted for the conventional configuration.